Merge StackBuilder into TaskBuilder

Since ActivityStack is merged into Task, we can merge StackBuilder into
TaskBuilder.

Also clean up some 'stack' terms and remove some unnecessary task levels.

Bug: 144248496
Bug: 155824575
Test: atest WmTests
Change-Id: I1600e8a4f3ed2a9bba3e6c344005b83563d7a164

20 files changed, 220 insertions, 249 deletions

diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityDisplayTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityDisplayTests.java
index 1eb45d587d33..cf07183a007d 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityDisplayTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityDisplayTests.java
@@ -67,7 +67,7 @@ public class ActivityDisplayTests extends WindowTestsBase {
         final TaskDisplayArea taskDisplayAreas =
                 mRootWindowContainer.getDefaultDisplay().getDefaultTaskDisplayArea();
         final Task stack =
-                new StackBuilder(mRootWindowContainer).setOnTop(!ON_TOP).build();
+                new TaskBuilder(mSupervisor).setOnTop(!ON_TOP).setCreateActivity(true).build();
         final Task prevFocusedStack = taskDisplayAreas.getFocusedStack();
 
         stack.moveToFront("moveStackToFront");
@@ -90,7 +90,7 @@ public class ActivityDisplayTests extends WindowTestsBase {
         final Task pinnedStack = mRootWindowContainer.getDefaultTaskDisplayArea()
                 .createStack(WINDOWING_MODE_PINNED, ACTIVITY_TYPE_STANDARD, ON_TOP);
         final Task pinnedTask = new TaskBuilder(mAtm.mStackSupervisor)
-                .setStack(pinnedStack).build();
+                .setParentTask(pinnedStack).build();
         new ActivityBuilder(mAtm).setActivityFlags(FLAG_ALWAYS_FOCUSABLE)
                 .setTask(pinnedTask).build();
         pinnedStack.moveToFront("movePinnedStackToFront");
@@ -144,7 +144,7 @@ public class ActivityDisplayTests extends WindowTestsBase {
         doReturn(false).when(display).shouldDestroyContentOnRemove();
 
         // Put home stack on the display.
-        final Task homeStack = new StackBuilder(mRootWindowContainer)
+        final Task homeStack = new TaskBuilder(mSupervisor)
                 .setDisplay(display).setActivityType(ACTIVITY_TYPE_HOME).build();
 
         // Put a finishing standard activity which will be reparented.
@@ -163,7 +163,7 @@ public class ActivityDisplayTests extends WindowTestsBase {
         final Task fullscreenStack = display.getDefaultTaskDisplayArea().createStack(
                 WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_STANDARD, ON_TOP);
         final Task fullscreenTask = new TaskBuilder(mAtm.mStackSupervisor)
-                .setStack(fullscreenStack).build();
+                .setParentTask(fullscreenStack).build();
         new ActivityBuilder(mAtm).setTask(fullscreenTask).build();
         return fullscreenStack;
     }
@@ -175,12 +175,11 @@ public class ActivityDisplayTests extends WindowTestsBase {
     public void testTopRunningActivity() {
         final DisplayContent display = mRootWindowContainer.getDefaultDisplay();
         final KeyguardController keyguard = mSupervisor.getKeyguardController();
-        final Task stack = new StackBuilder(mRootWindowContainer).build();
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         final ActivityRecord activity = stack.getTopNonFinishingActivity();
 
         // Create empty stack on top.
-        final Task emptyStack =
-                new StackBuilder(mRootWindowContainer).setCreateActivity(false).build();
+        final Task emptyStack = new TaskBuilder(mSupervisor).build();
 
         // Make sure the top running activity is not affected when keyguard is not locked.
         assertTopRunningActivity(activity, display);
@@ -322,10 +321,10 @@ public class ActivityDisplayTests extends WindowTestsBase {
                 ACTIVITY_TYPE_STANDARD, ON_TOP);
         final Task stack4 = taskDisplayArea.createStack(WINDOWING_MODE_FULLSCREEN,
                 ACTIVITY_TYPE_STANDARD, ON_TOP);
-        final Task task1 = new TaskBuilder(mAtm.mStackSupervisor).setStack(stack1).build();
-        final Task task2 = new TaskBuilder(mAtm.mStackSupervisor).setStack(stack2).build();
-        final Task task3 = new TaskBuilder(mAtm.mStackSupervisor).setStack(stack3).build();
-        final Task task4 = new TaskBuilder(mAtm.mStackSupervisor).setStack(stack4).build();
+        final Task task1 = new TaskBuilder(mAtm.mStackSupervisor).setParentTask(stack1).build();
+        final Task task2 = new TaskBuilder(mAtm.mStackSupervisor).setParentTask(stack2).build();
+        final Task task3 = new TaskBuilder(mAtm.mStackSupervisor).setParentTask(stack3).build();
+        final Task task4 = new TaskBuilder(mAtm.mStackSupervisor).setParentTask(stack4).build();
 
         // Reordering stacks while removing stacks.
         doAnswer(invocation -> {
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java
index eb78172cd562..e860f2508983 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityMetricsLaunchObserverTests.java
@@ -341,9 +341,8 @@ public class ActivityMetricsLaunchObserverTests extends WindowTestsBase {
     public void testConsecutiveLaunchOnDifferentDisplay() {
         onActivityLaunched(mTopActivity);
 
-        final Task stack = new StackBuilder(mRootWindowContainer)
+        final Task stack = new TaskBuilder(mSupervisor)
                 .setDisplay(addNewDisplayContentAt(DisplayContent.POSITION_BOTTOM))
-                .setCreateActivity(false)
                 .build();
         final ActivityRecord activityOnNewDisplay = new ActivityBuilder(mAtm)
                 .setStack(stack)
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityRecordTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityRecordTests.java
index bca990c659ae..09375db01888 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityRecordTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityRecordTests.java
@@ -131,7 +131,7 @@ public class ActivityRecordTests extends WindowTestsBase {
 
     @Before
     public void setUp() throws Exception {
-        mStack = new StackBuilder(mRootWindowContainer).build();
+        mStack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         mTask = mStack.getBottomMostTask();
         mActivity = mTask.getTopNonFinishingActivity();
 
@@ -172,7 +172,7 @@ public class ActivityRecordTests extends WindowTestsBase {
 
     @Test
     public void testNoCleanupMovingActivityInSameStack() {
-        final Task newTask = new TaskBuilder(mAtm.mStackSupervisor).setStack(mStack).build();
+        final Task newTask = new TaskBuilder(mAtm.mStackSupervisor).setParentTask(mStack).build();
         mActivity.reparent(newTask, 0, null /*reason*/);
         verify(mStack, times(0)).cleanUpActivityReferences(any());
     }
@@ -262,7 +262,7 @@ public class ActivityRecordTests extends WindowTestsBase {
 
         // Set options for two ActivityRecords in separate Tasks. Apply one ActivityRecord options.
         // Pending options should be cleared for only ActivityRecord that was applied
-        Task task2 = new TaskBuilder(mAtm.mStackSupervisor).setStack(mStack).build();
+        Task task2 = new TaskBuilder(mAtm.mStackSupervisor).setParentTask(mStack).build();
         activity2 = new ActivityBuilder(mAtm).setTask(task2).build();
         activity2.updateOptionsLocked(activityOptions);
         mActivity.updateOptionsLocked(activityOptions);
@@ -548,7 +548,7 @@ public class ActivityRecordTests extends WindowTestsBase {
                 .build();
         mActivity.setState(Task.ActivityState.STOPPED, "Testing");
 
-        final Task stack = new StackBuilder(mRootWindowContainer).build();
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         try {
             doReturn(false).when(stack).isTranslucent(any());
             assertFalse(mStack.shouldBeVisible(null /* starting */));
@@ -756,14 +756,14 @@ public class ActivityRecordTests extends WindowTestsBase {
     @Test
     public void testFinishActivityIfPossible_adjustStackOrder() {
         // Prepare the stacks with order (top to bottom): mStack, stack1, stack2.
-        final Task stack1 = new StackBuilder(mRootWindowContainer).build();
+        final Task stack1 = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         mStack.moveToFront("test");
         // The stack2 is needed here for moving back to simulate the
         // {@link DisplayContent#mPreferredTopFocusableStack} is cleared, so
         // {@link DisplayContent#getFocusedStack} will rely on the order of focusable-and-visible
         // stacks. Then when mActivity is finishing, its stack will be invisible (no running
         // activities in the stack) that is the key condition to verify.
-        final Task stack2 = new StackBuilder(mRootWindowContainer).build();
+        final Task stack2 = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         stack2.moveToBack("test", stack2.getBottomMostTask());
 
         assertTrue(mStack.isTopStackInDisplayArea());
@@ -973,7 +973,7 @@ public class ActivityRecordTests extends WindowTestsBase {
 
         // Simulates that {@code currentTop} starts an existing activity from background (so its
         // state is stopped) and the starting flow just goes to place it at top.
-        final Task nextStack = new StackBuilder(mRootWindowContainer).build();
+        final Task nextStack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         final ActivityRecord nextTop = nextStack.getTopNonFinishingActivity();
         nextTop.setState(STOPPED, "test");
 
@@ -1095,7 +1095,7 @@ public class ActivityRecordTests extends WindowTestsBase {
 
         // Add another stack to become focused and make the activity there visible. This way it
         // simulates finishing in non-focused stack in split-screen.
-        final Task stack = new StackBuilder(mRootWindowContainer).build();
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         final ActivityRecord focusedActivity = stack.getTopMostActivity();
         focusedActivity.nowVisible = true;
         focusedActivity.mVisibleRequested = true;
@@ -1581,7 +1581,7 @@ public class ActivityRecordTests extends WindowTestsBase {
 
         // Create a new task with custom config to reparent the activity to.
         final Task newTask =
-                new TaskBuilder(mSupervisor).setStack(initialTask.getRootTask()).build();
+                new TaskBuilder(mSupervisor).setParentTask(initialTask.getRootTask()).build();
         final Configuration newConfig = newTask.getConfiguration();
         newConfig.densityDpi += 100;
         newTask.onRequestedOverrideConfigurationChanged(newConfig);
@@ -1613,7 +1613,7 @@ public class ActivityRecordTests extends WindowTestsBase {
 
         // Create a new task with custom config to reparent the second activity to.
         final Task newTask =
-                new TaskBuilder(mSupervisor).setStack(initialTask.getRootTask()).build();
+                new TaskBuilder(mSupervisor).setParentTask(initialTask.getRootTask()).build();
         final Configuration newConfig = newTask.getConfiguration();
         newConfig.densityDpi += 100;
         newTask.onRequestedOverrideConfigurationChanged(newConfig);
@@ -1750,7 +1750,7 @@ public class ActivityRecordTests extends WindowTestsBase {
         }
         final Task stack = display.getDefaultTaskDisplayArea()
                 .createStack(WINDOWING_MODE_UNDEFINED, ACTIVITY_TYPE_STANDARD, true /* onTop */);
-        final Task task = new TaskBuilder(mSupervisor).setStack(stack).build();
+        final Task task = new TaskBuilder(mSupervisor).setParentTask(stack).build();
         return new ActivityBuilder(mAtm).setTask(task).setUseProcess(process).build();
     }
 }
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityStackSupervisorTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityStackSupervisorTests.java
index 27e2d1370fae..f9ad49bb5034 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityStackSupervisorTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityStackSupervisorTests.java
@@ -115,8 +115,8 @@ public class ActivityStackSupervisorTests extends WindowTestsBase {
     public void testHandleNonResizableTaskOnSecondaryDisplay() {
         // Create an unresizable task on secondary display.
         final DisplayContent newDisplay = addNewDisplayContentAt(DisplayContent.POSITION_TOP);
-        final Task stack = new StackBuilder(mRootWindowContainer)
-                .setDisplay(newDisplay).build();
+        final Task stack = new TaskBuilder(mSupervisor)
+                .setDisplay(newDisplay).setCreateActivity(true).build();
         final ActivityRecord unresizableActivity = stack.getTopNonFinishingActivity();
         final Task task = unresizableActivity.getTask();
         unresizableActivity.info.resizeMode = ActivityInfo.RESIZE_MODE_UNRESIZEABLE;
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityStackTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityStackTests.java
index 524f32deb864..4951658bbd78 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityStackTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityStackTests.java
@@ -100,7 +100,7 @@ public class ActivityStackTests extends WindowTestsBase {
         mStack = mDefaultTaskDisplayArea.createStack(WINDOWING_MODE_UNDEFINED,
                 ACTIVITY_TYPE_STANDARD, true /* onTop */);
         spyOn(mStack);
-        mTask = new TaskBuilder(mSupervisor).setStack(mStack).build();
+        mTask = new TaskBuilder(mSupervisor).setParentTask(mStack).build();
     }
 
     @Test
@@ -330,7 +330,7 @@ public class ActivityStackTests extends WindowTestsBase {
                 targetActivity);
         final ComponentName alias = new ComponentName(DEFAULT_COMPONENT_PACKAGE_NAME,
                 aliasActivity);
-        final Task task = new TaskBuilder(mAtm.mStackSupervisor).setStack(mStack).build();
+        final Task task = new TaskBuilder(mAtm.mStackSupervisor).setParentTask(mStack).build();
         task.origActivity = alias;
         task.realActivity = target;
         new ActivityBuilder(mAtm).setComponent(target).setTask(task).setTargetActivity(
@@ -995,7 +995,7 @@ public class ActivityStackTests extends WindowTestsBase {
             mDefaultTaskDisplayArea.positionChildAt(onTop ? POSITION_TOP : POSITION_BOTTOM, task,
                     false /* includingParents */);
         } else {
-            task = new StackBuilder(mRootWindowContainer)
+            task = new TaskBuilder(mSupervisor)
                     .setTaskDisplayArea(taskDisplayArea)
                     .setWindowingMode(windowingMode)
                     .setActivityType(activityType)
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityStarterTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityStarterTests.java
index e537b7c204cc..076047b35604 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityStarterTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityStarterTests.java
@@ -217,7 +217,10 @@ public class ActivityStarterTests extends WindowTestsBase {
 
         // Create source token
         final ActivityBuilder builder = new ActivityBuilder(service).setTask(
-                new TaskBuilder(service.mStackSupervisor).setVoiceSession(voiceSession).build());
+                new TaskBuilder(service.mStackSupervisor)
+                        .setVoiceSession(voiceSession)
+                        .setCreateParentTask(true)
+                        .build());
 
         if (aInfo != null) {
             aInfo.applicationInfo = new ApplicationInfo();
@@ -706,7 +709,9 @@ public class ActivityStarterTests extends WindowTestsBase {
     @Test
     public void testBringTaskToFrontWhenFocusedStackIsFinising() {
         // Put 2 tasks in the same stack (simulate the behavior of home stack).
+        final Task rootTask = new TaskBuilder(mSupervisor).build();
         final ActivityRecord activity = new ActivityBuilder(mAtm)
+                .setStack(rootTask)
                 .setCreateTask(true).build();
         new ActivityBuilder(mAtm)
                 .setStack(activity.getRootTask())
@@ -792,7 +797,7 @@ public class ActivityStarterTests extends WindowTestsBase {
         // Create another activity on top of the secondary display.
         final Task topStack = secondaryTaskContainer.createStack(WINDOWING_MODE_FULLSCREEN,
                 ACTIVITY_TYPE_STANDARD, true /* onTop */);
-        final Task topTask = new TaskBuilder(mSupervisor).setStack(topStack).build();
+        final Task topTask = new TaskBuilder(mSupervisor).setParentTask(topStack).build();
         new ActivityBuilder(mAtm).setTask(topTask).build();
 
         // Start activity with the same intent as {@code singleTaskActivity} on secondary display.
@@ -851,7 +856,7 @@ public class ActivityStarterTests extends WindowTestsBase {
                 DEFAULT_COMPONENT_PACKAGE_NAME + ".SingleTaskActivity");
         final Task task = new TaskBuilder(mSupervisor)
                 .setComponent(componentName)
-                .setStack(stack)
+                .setParentTask(stack)
                 .build();
         return new ActivityBuilder(mAtm)
                 .setComponent(componentName)
@@ -987,7 +992,7 @@ public class ActivityStarterTests extends WindowTestsBase {
         final ActivityStarter starter = prepareStarter(0 /* flags */);
         starter.mStartActivity = new ActivityBuilder(mAtm).build();
         final Task task = new TaskBuilder(mAtm.mStackSupervisor)
-                .setStack(mAtm.mRootWindowContainer.getDefaultTaskDisplayArea().createStack(
+                .setParentTask(mAtm.mRootWindowContainer.getDefaultTaskDisplayArea().createStack(
                         WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_STANDARD, true /* onTop */))
                 .setUserId(10)
                 .build();
diff --git a/services/tests/wmtests/src/com/android/server/wm/ActivityTaskManagerServiceTests.java b/services/tests/wmtests/src/com/android/server/wm/ActivityTaskManagerServiceTests.java
index 567610018fc1..031165727207 100644
--- a/services/tests/wmtests/src/com/android/server/wm/ActivityTaskManagerServiceTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/ActivityTaskManagerServiceTests.java
@@ -73,7 +73,7 @@ public class ActivityTaskManagerServiceTests extends WindowTestsBase {
     /** Verify that activity is finished correctly upon request. */
     @Test
     public void testActivityFinish() {
-        final Task stack = new StackBuilder(mRootWindowContainer).build();
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         final ActivityRecord activity = stack.getBottomMostTask().getTopNonFinishingActivity();
         assertTrue("Activity must be finished", mAtm.finishActivity(activity.appToken,
                 0 /* resultCode */, null /* resultData */,
@@ -87,7 +87,7 @@ public class ActivityTaskManagerServiceTests extends WindowTestsBase {
 
     @Test
     public void testOnPictureInPictureRequested() throws RemoteException {
-        final Task stack = new StackBuilder(mRootWindowContainer).build();
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         final ActivityRecord activity = stack.getBottomMostTask().getTopNonFinishingActivity();
         final ClientLifecycleManager mockLifecycleManager = mock(ClientLifecycleManager.class);
         doReturn(mockLifecycleManager).when(mAtm).getLifecycleManager();
@@ -106,7 +106,7 @@ public class ActivityTaskManagerServiceTests extends WindowTestsBase {
 
     @Test(expected = IllegalStateException.class)
     public void testOnPictureInPictureRequested_cannotEnterPip() throws RemoteException {
-        final Task stack = new StackBuilder(mRootWindowContainer).build();
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         final ActivityRecord activity = stack.getBottomMostTask().getTopNonFinishingActivity();
         ClientLifecycleManager lifecycleManager = mAtm.getLifecycleManager();
         doReturn(false).when(activity).inPinnedWindowingMode();
@@ -120,7 +120,7 @@ public class ActivityTaskManagerServiceTests extends WindowTestsBase {
 
     @Test(expected = IllegalStateException.class)
     public void testOnPictureInPictureRequested_alreadyInPIPMode() throws RemoteException {
-        final Task stack = new StackBuilder(mRootWindowContainer).build();
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         final ActivityRecord activity = stack.getBottomMostTask().getTopNonFinishingActivity();
         ClientLifecycleManager lifecycleManager = mAtm.getLifecycleManager();
         doReturn(true).when(activity).inPinnedWindowingMode();
diff --git a/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java b/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java
index f8baf8497069..3cfda8df7d5c 100644
--- a/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/DisplayContentTests.java
@@ -847,17 +847,17 @@ public class DisplayContentTests extends WindowTestsBase {
         dc.getDisplayRotation().setFixedToUserRotation(
                 IWindowManager.FIXED_TO_USER_ROTATION_DISABLED);
 
-        final Task stack =
-                new StackBuilder(mWm.mAtmService.mRootWindowContainer)
-                        .setDisplay(dc)
-                        .build();
+        final Task stack = new TaskBuilder(mSupervisor)
+                .setDisplay(dc)
+                .setCreateActivity(true)
+                .build();
         doReturn(true).when(stack).isVisible();
 
-        final Task freeformStack =
-                new StackBuilder(mWm.mAtmService.mRootWindowContainer)
-                        .setDisplay(dc)
-                        .setWindowingMode(WINDOWING_MODE_FREEFORM)
-                        .build();
+        final Task freeformStack = new TaskBuilder(mSupervisor)
+                .setDisplay(dc)
+                .setCreateActivity(true)
+                .setWindowingMode(WINDOWING_MODE_FREEFORM)
+                .build();
         doReturn(true).when(freeformStack).isVisible();
         freeformStack.getTopChild().setBounds(100, 100, 300, 400);
 
@@ -879,8 +879,8 @@ public class DisplayContentTests extends WindowTestsBase {
                 IWindowManager.FIXED_TO_USER_ROTATION_DISABLED);
         final int newOrientation = getRotatedOrientation(dc);
 
-        final Task stack = new StackBuilder(mWm.mAtmService.mRootWindowContainer)
-                .setDisplay(dc).build();
+        final Task stack = new TaskBuilder(mSupervisor)
+                .setDisplay(dc).setCreateActivity(true).build();
         final ActivityRecord activity = stack.getTopMostTask().getTopNonFinishingActivity();
 
         activity.setRequestedOrientation(newOrientation);
@@ -898,8 +898,8 @@ public class DisplayContentTests extends WindowTestsBase {
                 IWindowManager.FIXED_TO_USER_ROTATION_ENABLED);
         final int newOrientation = getRotatedOrientation(dc);
 
-        final Task stack = new StackBuilder(mWm.mAtmService.mRootWindowContainer)
-                .setDisplay(dc).build();
+        final Task stack = new TaskBuilder(mSupervisor)
+                .setDisplay(dc).setCreateActivity(true).build();
         final ActivityRecord activity = stack.getTopMostTask().getTopNonFinishingActivity();
 
         activity.setRequestedOrientation(newOrientation);
@@ -1209,8 +1209,8 @@ public class DisplayContentTests extends WindowTestsBase {
         verify(t, never()).setPosition(any(), eq(0), eq(0));
 
         // Launch another activity before the transition is finished.
-        final ActivityRecord app2 = new StackBuilder(mWm.mRoot)
-                .setDisplay(mDisplayContent).build().getTopMostActivity();
+        final ActivityRecord app2 = new TaskBuilder(mSupervisor)
+                .setDisplay(mDisplayContent).setCreateActivity(true).build().getTopMostActivity();
         app2.setVisible(false);
         mDisplayContent.mOpeningApps.add(app2);
         app2.setRequestedOrientation(newOrientation);
@@ -1508,7 +1508,7 @@ public class DisplayContentTests extends WindowTestsBase {
     @Test
     public void testSetWindowingModeAtomicallyUpdatesWindoingModeAndDisplayWindowingMode() {
         final DisplayContent dc = createNewDisplay();
-        final Task stack = new StackBuilder(mWm.mAtmService.mRootWindowContainer)
+        final Task stack = new TaskBuilder(mSupervisor)
                 .setDisplay(dc)
                 .build();
         doAnswer(invocation -> {
diff --git a/services/tests/wmtests/src/com/android/server/wm/LaunchParamsPersisterTests.java b/services/tests/wmtests/src/com/android/server/wm/LaunchParamsPersisterTests.java
index 18a2d1337d4b..d701a9df7cb8 100644
--- a/services/tests/wmtests/src/com/android/server/wm/LaunchParamsPersisterTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/LaunchParamsPersisterTests.java
@@ -116,7 +116,7 @@ public class LaunchParamsPersisterTests extends WindowTestsBase {
 
         Task stack = mTestDisplay.getDefaultTaskDisplayArea()
                 .createStack(TEST_WINDOWING_MODE, ACTIVITY_TYPE_STANDARD, /* onTop */ true);
-        mTestTask = new TaskBuilder(mSupervisor).setComponent(TEST_COMPONENT).setStack(stack)
+        mTestTask = new TaskBuilder(mSupervisor).setComponent(TEST_COMPONENT).setParentTask(stack)
                 .build();
         mTestTask.mUserId = TEST_USER_ID;
         mTestTask.mLastNonFullscreenBounds = TEST_BOUNDS;
@@ -342,7 +342,7 @@ public class LaunchParamsPersisterTests extends WindowTestsBase {
         final Task anotherTaskOfTheSameUser = new TaskBuilder(mSupervisor)
                 .setComponent(ALTERNATIVE_COMPONENT)
                 .setUserId(TEST_USER_ID)
-                .setStack(stack)
+                .setParentTask(stack)
                 .build();
         anotherTaskOfTheSameUser.setWindowingMode(WINDOWING_MODE_FREEFORM);
         anotherTaskOfTheSameUser.setBounds(200, 300, 400, 500);
@@ -354,7 +354,7 @@ public class LaunchParamsPersisterTests extends WindowTestsBase {
         final Task anotherTaskOfDifferentUser = new TaskBuilder(mSupervisor)
                 .setComponent(TEST_COMPONENT)
                 .setUserId(ALTERNATIVE_USER_ID)
-                .setStack(stack)
+                .setParentTask(stack)
                 .build();
         anotherTaskOfDifferentUser.setWindowingMode(WINDOWING_MODE_FREEFORM);
         anotherTaskOfDifferentUser.setBounds(300, 400, 500, 600);
diff --git a/services/tests/wmtests/src/com/android/server/wm/RecentTasksTest.java b/services/tests/wmtests/src/com/android/server/wm/RecentTasksTest.java
index 9954f484f0a6..253fbae4579b 100644
--- a/services/tests/wmtests/src/com/android/server/wm/RecentTasksTest.java
+++ b/services/tests/wmtests/src/com/android/server/wm/RecentTasksTest.java
@@ -333,10 +333,10 @@ public class RecentTasksTest extends WindowTestsBase {
         // other task
         Task task1 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_MULTIPLE_TASK)
-                .setStack(mTaskContainer.getRootHomeTask()).build();
+                .setParentTask(mTaskContainer.getRootHomeTask()).build();
         Task task2 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK | FLAG_ACTIVITY_MULTIPLE_TASK)
-                .setStack(mStack).build();
+                .setParentTask(mStack).build();
         mRecentTasks.add(task1);
         mRecentTasks.add(task2);
         assertThat(mCallbacksRecorder.mAdded).hasSize(2);
@@ -352,7 +352,7 @@ public class RecentTasksTest extends WindowTestsBase {
         // and we want to ensure that a new task will match a restored task
         Task task1 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK)
-                .setStack(mStack)
+                .setParentTask(mStack)
                 .build();
         setTaskActivityType(task1, ACTIVITY_TYPE_UNDEFINED);
         assertThat(task1.getActivityType()).isEqualTo(ACTIVITY_TYPE_UNDEFINED);
@@ -361,7 +361,7 @@ public class RecentTasksTest extends WindowTestsBase {
 
         Task task2 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK)
-                .setStack(mStack)
+                .setParentTask(mStack)
                 .build();
         assertEquals(ACTIVITY_TYPE_STANDARD, task2.getActivityType());
         mRecentTasks.add(task2);
@@ -376,7 +376,7 @@ public class RecentTasksTest extends WindowTestsBase {
     public void testAddTaskCompatibleActivityTypeDifferentUser_expectNoRemove() {
         Task task1 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK)
-                .setStack(mStack)
+                .setParentTask(mStack)
                 .setUserId(TEST_USER_0_ID)
                 .build();
         setTaskActivityType(task1, ACTIVITY_TYPE_UNDEFINED);
@@ -386,7 +386,7 @@ public class RecentTasksTest extends WindowTestsBase {
 
         Task task2 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK)
-                .setStack(mStack)
+                .setParentTask(mStack)
                 .setUserId(TEST_USER_1_ID)
                 .build();
         assertEquals(ACTIVITY_TYPE_STANDARD, task2.getActivityType());
@@ -401,7 +401,7 @@ public class RecentTasksTest extends WindowTestsBase {
     public void testAddTaskCompatibleWindowingMode_expectRemove() {
         Task task1 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK)
-                .setStack(mStack)
+                .setParentTask(mStack)
                 .build();
         setTaskWindowingMode(task1, WINDOWING_MODE_UNDEFINED);
         assertEquals(WINDOWING_MODE_UNDEFINED, task1.getWindowingMode());
@@ -410,7 +410,7 @@ public class RecentTasksTest extends WindowTestsBase {
 
         Task task2 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK)
-                .setStack(mStack)
+                .setParentTask(mStack)
                 .build();
         setTaskWindowingMode(task2, WINDOWING_MODE_FULLSCREEN);
         assertEquals(WINDOWING_MODE_FULLSCREEN, task2.getWindowingMode());
@@ -427,7 +427,7 @@ public class RecentTasksTest extends WindowTestsBase {
     public void testAddTaskIncompatibleWindowingMode_expectNoRemove() {
         Task task1 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK)
-                .setStack(mStack)
+                .setParentTask(mStack)
                 .build();
         setTaskWindowingMode(task1, WINDOWING_MODE_FULLSCREEN);
         assertEquals(WINDOWING_MODE_FULLSCREEN, task1.getWindowingMode());
@@ -435,7 +435,7 @@ public class RecentTasksTest extends WindowTestsBase {
 
         Task task2 = createTaskBuilder(".Task1")
                 .setFlags(FLAG_ACTIVITY_NEW_TASK)
-                .setStack(mStack)
+                .setParentTask(mStack)
                 .build();
         setTaskWindowingMode(task2, WINDOWING_MODE_PINNED);
         assertEquals(WINDOWING_MODE_PINNED, task2.getWindowingMode());
@@ -453,19 +453,19 @@ public class RecentTasksTest extends WindowTestsBase {
         // Add task to recents
         final String taskAffinity = "affinity";
         final int uid = 10123;
-        final Task task1 = createTaskBuilder(".Task1").setStack(mStack).build();
+        final Task task1 = createTaskBuilder(".Task1").setParentTask(mStack).build();
         task1.affinity = ActivityRecord.computeTaskAffinity(taskAffinity, uid, LAUNCH_MULTIPLE);
         mRecentTasks.add(task1);
 
         // Add another task to recents, and make sure the previous task was removed.
-        final Task task2 = createTaskBuilder(".Task2").setStack(mStack).build();
+        final Task task2 = createTaskBuilder(".Task2").setParentTask(mStack).build();
         task2.affinity = ActivityRecord.computeTaskAffinity(taskAffinity, uid, LAUNCH_MULTIPLE);
         mRecentTasks.add(task2);
         assertEquals(1, mRecentTasks.getRecentTasks(MAX_VALUE, 0 /* flags */,
                 true /* getTasksAllowed */, TEST_USER_0_ID, 0).getList().size());
 
         // Add another single-instance task to recents, and make sure no task is removed.
-        final Task task3 = createTaskBuilder(".Task3").setStack(mStack).build();
+        final Task task3 = createTaskBuilder(".Task3").setParentTask(mStack).build();
         task3.affinity = ActivityRecord.computeTaskAffinity(taskAffinity, uid,
                 LAUNCH_SINGLE_INSTANCE);
         mRecentTasks.add(task3);
@@ -497,7 +497,7 @@ public class RecentTasksTest extends WindowTestsBase {
         // tasks because their intents are identical.
         mRecentTasks.add(task1);
         // Go home to trigger the removal of untracked tasks.
-        mRecentTasks.add(createTaskBuilder(".Home").setStack(mTaskContainer.getRootHomeTask())
+        mRecentTasks.add(createTaskBuilder(".Home").setParentTask(mTaskContainer.getRootHomeTask())
                 .build());
 
         // The task was added into recents again so it is not hidden and shouldn't be removed.
@@ -883,10 +883,10 @@ public class RecentTasksTest extends WindowTestsBase {
 
         // Add a number of tasks (beyond the max) but ensure that nothing is trimmed because all
         // the tasks belong in stacks above the home stack
-        mRecentTasks.add(createTaskBuilder(".HomeTask1").setStack(homeStack).build());
-        mRecentTasks.add(createTaskBuilder(".Task1").setStack(aboveHomeStack).build());
-        mRecentTasks.add(createTaskBuilder(".Task2").setStack(aboveHomeStack).build());
-        mRecentTasks.add(createTaskBuilder(".Task3").setStack(aboveHomeStack).build());
+        mRecentTasks.add(createTaskBuilder(".HomeTask1").setParentTask(homeStack).build());
+        mRecentTasks.add(createTaskBuilder(".Task1").setParentTask(aboveHomeStack).build());
+        mRecentTasks.add(createTaskBuilder(".Task2").setParentTask(aboveHomeStack).build());
+        mRecentTasks.add(createTaskBuilder(".Task3").setParentTask(aboveHomeStack).build());
 
         assertNoTasksTrimmed();
     }
@@ -904,11 +904,11 @@ public class RecentTasksTest extends WindowTestsBase {
         // Add a number of tasks (beyond the max) but ensure that only the task in the stack behind
         // the home stack is trimmed once a new task is added
         final Task behindHomeTask = createTaskBuilder(".Task1")
-                .setStack(behindHomeStack)
+                .setParentTask(behindHomeStack)
                 .build();
         mRecentTasks.add(behindHomeTask);
-        mRecentTasks.add(createTaskBuilder(".HomeTask1").setStack(homeStack).build());
-        mRecentTasks.add(createTaskBuilder(".Task2").setStack(aboveHomeStack).build());
+        mRecentTasks.add(createTaskBuilder(".HomeTask1").setParentTask(homeStack).build());
+        mRecentTasks.add(createTaskBuilder(".Task2").setParentTask(aboveHomeStack).build());
 
         assertTrimmed(behindHomeTask);
     }
@@ -924,10 +924,10 @@ public class RecentTasksTest extends WindowTestsBase {
 
         // Add a number of tasks (beyond the max) on each display, ensure that the tasks are not
         // removed
-        mRecentTasks.add(createTaskBuilder(".HomeTask1").setStack(homeStack).build());
-        mRecentTasks.add(createTaskBuilder(".Task1").setStack(otherDisplayStack).build());
-        mRecentTasks.add(createTaskBuilder(".Task2").setStack(otherDisplayStack).build());
-        mRecentTasks.add(createTaskBuilder(".HomeTask2").setStack(homeStack).build());
+        mRecentTasks.add(createTaskBuilder(".HomeTask1").setParentTask(homeStack).build());
+        mRecentTasks.add(createTaskBuilder(".Task1").setParentTask(otherDisplayStack).build());
+        mRecentTasks.add(createTaskBuilder(".Task2").setParentTask(otherDisplayStack).build());
+        mRecentTasks.add(createTaskBuilder(".HomeTask2").setParentTask(homeStack).build());
 
         assertNoTasksTrimmed();
     }
@@ -1214,7 +1214,7 @@ public class RecentTasksTest extends WindowTestsBase {
     private TaskBuilder createTaskBuilder(String packageName, String className) {
         return new TaskBuilder(mAtm.mStackSupervisor)
                 .setComponent(new ComponentName(packageName, className))
-                .setStack(mStack)
+                .setParentTask(mStack)
                 .setUserId(TEST_USER_0_ID);
     }
 
diff --git a/services/tests/wmtests/src/com/android/server/wm/RootActivityContainerTests.java b/services/tests/wmtests/src/com/android/server/wm/RootActivityContainerTests.java
index 26b0bfb1dd7c..901ed36254ea 100644
--- a/services/tests/wmtests/src/com/android/server/wm/RootActivityContainerTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/RootActivityContainerTests.java
@@ -195,8 +195,7 @@ public class RootActivityContainerTests extends WindowTestsBase {
     public void testApplySleepTokens() {
         final DisplayContent display = mRootWindowContainer.getDefaultDisplay();
         final KeyguardController keyguard = mSupervisor.getKeyguardController();
-        final Task stack = new StackBuilder(mRootWindowContainer)
-                .setCreateActivity(false)
+        final Task stack = new TaskBuilder(mSupervisor)
                 .setDisplay(display)
                 .setOnTop(false)
                 .build();
@@ -384,7 +383,7 @@ public class RootActivityContainerTests extends WindowTestsBase {
         final Task primaryStack = mRootWindowContainer.getDefaultTaskDisplayArea()
                 .createStack(WINDOWING_MODE_SPLIT_SCREEN_PRIMARY, ACTIVITY_TYPE_STANDARD,
                         true /* onTop */);
-        final Task task = new TaskBuilder(mSupervisor).setStack(primaryStack).build();
+        final Task task = new TaskBuilder(mSupervisor).setParentTask(primaryStack).build();
         final ActivityRecord r = new ActivityBuilder(mAtm).setTask(task).build();
 
         // Find a launch stack for the top activity in split-screen primary, while requesting
@@ -404,14 +403,17 @@ public class RootActivityContainerTests extends WindowTestsBase {
     @Test
     public void testFindTaskToMoveToFrontWhenRecentsOnTop() {
         // Create stack/task on default display.
-        final Task targetStack = new StackBuilder(mRootWindowContainer)
+        final Task targetStack = new TaskBuilder(mSupervisor)
+                .setCreateActivity(true)
                 .setOnTop(false)
                 .build();
         final Task targetTask = targetStack.getBottomMostTask();
 
         // Create Recents on top of the display.
-        final Task stack = new StackBuilder(mRootWindowContainer).setActivityType(
-                ACTIVITY_TYPE_RECENTS).build();
+        final Task stack = new TaskBuilder(mSupervisor)
+                .setCreateActivity(true)
+                .setActivityType(ACTIVITY_TYPE_RECENTS)
+                .build();
 
         final String reason = "findTaskToMoveToFront";
         mSupervisor.findTaskToMoveToFront(targetTask, 0, ActivityOptions.makeBasic(), reason,
@@ -431,14 +433,14 @@ public class RootActivityContainerTests extends WindowTestsBase {
         final TaskDisplayArea taskDisplayArea = mRootWindowContainer.getDefaultTaskDisplayArea();
         final Task targetStack = taskDisplayArea.createStack(WINDOWING_MODE_FULLSCREEN,
                 ACTIVITY_TYPE_STANDARD, false /* onTop */);
-        final Task targetTask = new TaskBuilder(mSupervisor).setStack(targetStack).build();
+        final Task targetTask = new TaskBuilder(mSupervisor).setParentTask(targetStack).build();
 
         // Create Recents on secondary display.
         final TestDisplayContent secondDisplay = addNewDisplayContentAt(
                 DisplayContent.POSITION_TOP);
         final Task stack = secondDisplay.getDefaultTaskDisplayArea()
                 .createStack(WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_RECENTS, true /* onTop */);
-        final Task task = new TaskBuilder(mSupervisor).setStack(stack).build();
+        final Task task = new TaskBuilder(mSupervisor).setParentTask(stack).build();
         new ActivityBuilder(mAtm).setTask(task).build();
 
         final String reason = "findTaskToMoveToFront";
@@ -458,7 +460,7 @@ public class RootActivityContainerTests extends WindowTestsBase {
         final TaskDisplayArea taskDisplayArea = mRootWindowContainer.getDefaultTaskDisplayArea();
         final Task targetStack = spy(taskDisplayArea.createStack(WINDOWING_MODE_FULLSCREEN,
                 ACTIVITY_TYPE_STANDARD, false /* onTop */));
-        final Task task = new TaskBuilder(mSupervisor).setStack(targetStack).build();
+        final Task task = new TaskBuilder(mSupervisor).setParentTask(targetStack).build();
         final ActivityRecord activity = new ActivityBuilder(mAtm).setTask(task).build();
         taskDisplayArea.positionChildAt(POSITION_BOTTOM, targetStack, false /*includingParents*/);
 
@@ -514,7 +516,7 @@ public class RootActivityContainerTests extends WindowTestsBase {
                 DisplayContent.POSITION_TOP);
         final Task stack = secondDisplay.getDefaultTaskDisplayArea()
                 .createStack(WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_STANDARD, true /* onTop */);
-        final Task task = new TaskBuilder(mSupervisor).setStack(stack).build();
+        final Task task = new TaskBuilder(mSupervisor).setParentTask(stack).build();
         new ActivityBuilder(mAtm).setTask(task).build();
 
         doReturn(true).when(mRootWindowContainer).resumeHomeActivity(any(), any(), any());
@@ -538,7 +540,7 @@ public class RootActivityContainerTests extends WindowTestsBase {
         final TaskDisplayArea taskDisplayArea = mRootWindowContainer.getDefaultTaskDisplayArea();
         final Task targetStack = spy(taskDisplayArea.createStack(WINDOWING_MODE_FULLSCREEN,
                 ACTIVITY_TYPE_STANDARD, false /* onTop */));
-        final Task task = new TaskBuilder(mSupervisor).setStack(targetStack).build();
+        final Task task = new TaskBuilder(mSupervisor).setParentTask(targetStack).build();
         final ActivityRecord activity = new ActivityBuilder(mAtm).setTask(task).build();
         activity.setState(ActivityState.RESUMED, "test");
 
@@ -558,7 +560,7 @@ public class RootActivityContainerTests extends WindowTestsBase {
         final TaskDisplayArea taskDisplayArea = mRootWindowContainer.getDefaultTaskDisplayArea();
         final Task targetStack = spy(taskDisplayArea.createStack(WINDOWING_MODE_FULLSCREEN,
                 ACTIVITY_TYPE_STANDARD, false /* onTop */));
-        final Task task = new TaskBuilder(mSupervisor).setStack(targetStack).build();
+        final Task task = new TaskBuilder(mSupervisor).setParentTask(targetStack).build();
         final ActivityRecord activity = new ActivityBuilder(mAtm).setTask(task).build();
         activity.setState(ActivityState.RESUMED, "test");
         taskDisplayArea.positionChildAt(POSITION_BOTTOM, targetStack, false /*includingParents*/);
@@ -884,7 +886,7 @@ public class RootActivityContainerTests extends WindowTestsBase {
         // Create a root task with an activity on secondary display.
         final TestDisplayContent secondaryDisplay = new TestDisplayContent.Builder(mAtm, 300,
                 600).build();
-        final Task task = new StackBuilder(mRootWindowContainer)
+        final Task task = new TaskBuilder(mSupervisor)
                 .setDisplay(secondaryDisplay).build();
         final ActivityRecord activity = new ActivityBuilder(mAtm).setTask(task).build();
 
diff --git a/services/tests/wmtests/src/com/android/server/wm/RootWindowContainerTests.java b/services/tests/wmtests/src/com/android/server/wm/RootWindowContainerTests.java
index 191c33c61aca..3053fe6ec55f 100644
--- a/services/tests/wmtests/src/com/android/server/wm/RootWindowContainerTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/RootWindowContainerTests.java
@@ -174,7 +174,7 @@ public class RootWindowContainerTests extends WindowTestsBase {
 
     @Test
     public void testForceStopPackage() {
-        final Task task = new StackBuilder(mWm.mRoot).build();
+        final Task task = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         final ActivityRecord activity = task.getTopMostActivity();
         final WindowProcessController wpc = activity.app;
         final ActivityRecord[] activities = {
diff --git a/services/tests/wmtests/src/com/android/server/wm/RunningTasksTest.java b/services/tests/wmtests/src/com/android/server/wm/RunningTasksTest.java
index 341509310e26..8a5b13c0bdce 100644
--- a/services/tests/wmtests/src/com/android/server/wm/RunningTasksTest.java
+++ b/services/tests/wmtests/src/com/android/server/wm/RunningTasksTest.java
@@ -62,8 +62,7 @@ public class RunningTasksTest extends WindowTestsBase {
 
         final int numStacks = 2;
         for (int stackIndex = 0; stackIndex < numStacks; stackIndex++) {
-            final Task stack = new StackBuilder(mRootWindowContainer)
-                    .setCreateActivity(false)
+            final Task stack = new TaskBuilder(mSupervisor)
                     .setDisplay(display)
                     .setOnTop(false)
                     .build();
@@ -104,8 +103,7 @@ public class RunningTasksTest extends WindowTestsBase {
         final DisplayContent display = new TestDisplayContent.Builder(mAtm, 1000, 2500).build();
         final int numTasks = 10;
         for (int i = 0; i < numTasks; i++) {
-            final Task stack = new StackBuilder(mRootWindowContainer)
-                    .setCreateActivity(false)
+            final Task stack = new TaskBuilder(mSupervisor)
                     .setDisplay(display)
                     .setOnTop(true)
                     .build();
@@ -135,7 +133,7 @@ public class RunningTasksTest extends WindowTestsBase {
         final Task task = new TaskBuilder(mAtm.mStackSupervisor)
                 .setComponent(new ComponentName(mContext.getPackageName(), className))
                 .setTaskId(taskId)
-                .setStack(stack)
+                .setParentTask(stack)
                 .build();
         task.lastActiveTime = lastActiveTime;
         final ActivityRecord activity = new ActivityBuilder(mAtm)
diff --git a/services/tests/wmtests/src/com/android/server/wm/SizeCompatTests.java b/services/tests/wmtests/src/com/android/server/wm/SizeCompatTests.java
index 468b2c35ffc2..29081d389225 100644
--- a/services/tests/wmtests/src/com/android/server/wm/SizeCompatTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/SizeCompatTests.java
@@ -72,7 +72,7 @@ public class SizeCompatTests extends WindowTestsBase {
     private ActivityRecord mActivity;
 
     private void setUpApp(DisplayContent display) {
-        mStack = new StackBuilder(mRootWindowContainer).setDisplay(display).build();
+        mStack = new TaskBuilder(mSupervisor).setDisplay(display).setCreateActivity(true).build();
         mTask = mStack.getBottomMostTask();
         mActivity = mTask.getTopNonFinishingActivity();
     }
diff --git a/services/tests/wmtests/src/com/android/server/wm/TaskDisplayAreaTests.java b/services/tests/wmtests/src/com/android/server/wm/TaskDisplayAreaTests.java
index 260f1e9a9259..bc3b3a4d7ad1 100644
--- a/services/tests/wmtests/src/com/android/server/wm/TaskDisplayAreaTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/TaskDisplayAreaTests.java
@@ -218,7 +218,7 @@ public class TaskDisplayAreaTests extends WindowTestsBase {
         final Task rootHomeTask = defaultTaskDisplayArea.getRootHomeTask();
         rootHomeTask.mResizeMode = RESIZE_MODE_UNRESIZEABLE;
 
-        final Task primarySplitTask = new StackBuilder(rootWindowContainer)
+        final Task primarySplitTask = new TaskBuilder(mSupervisor)
                 .setTaskDisplayArea(defaultTaskDisplayArea)
                 .setWindowingMode(WINDOWING_MODE_SPLIT_SCREEN_PRIMARY)
                 .setActivityType(ACTIVITY_TYPE_STANDARD)
diff --git a/services/tests/wmtests/src/com/android/server/wm/TaskLaunchParamsModifierTests.java b/services/tests/wmtests/src/com/android/server/wm/TaskLaunchParamsModifierTests.java
index 42de5e6b429d..1d32e17dd5e1 100644
--- a/services/tests/wmtests/src/com/android/server/wm/TaskLaunchParamsModifierTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/TaskLaunchParamsModifierTests.java
@@ -1358,7 +1358,7 @@ public class TaskLaunchParamsModifierTests extends WindowTestsBase {
         final Task stack = display.getDefaultTaskDisplayArea()
                 .createStack(display.getWindowingMode(), ACTIVITY_TYPE_STANDARD, true);
         stack.setWindowingMode(WINDOWING_MODE_FREEFORM);
-        final Task task = new TaskBuilder(mSupervisor).setStack(stack).build();
+        final Task task = new TaskBuilder(mSupervisor).setParentTask(stack).build();
         // Just work around the unnecessary adjustments for bounds.
         task.getWindowConfiguration().setBounds(bounds);
     }
diff --git a/services/tests/wmtests/src/com/android/server/wm/TaskRecordTests.java b/services/tests/wmtests/src/com/android/server/wm/TaskRecordTests.java
index 08537a4ea9c1..a908bfef98de 100644
--- a/services/tests/wmtests/src/com/android/server/wm/TaskRecordTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/TaskRecordTests.java
@@ -176,7 +176,7 @@ public class TaskRecordTests extends WindowTestsBase {
         TaskDisplayArea taskDisplayArea = mAtm.mRootWindowContainer.getDefaultTaskDisplayArea();
         Task stack = taskDisplayArea.createStack(WINDOWING_MODE_FREEFORM,
                 ACTIVITY_TYPE_STANDARD, true /* onTop */);
-        Task task = new TaskBuilder(mSupervisor).setStack(stack).build();
+        Task task = new TaskBuilder(mSupervisor).setParentTask(stack).build();
         final Configuration parentConfig = stack.getConfiguration();
         parentConfig.windowConfiguration.setBounds(parentBounds);
         parentConfig.densityDpi = DisplayMetrics.DENSITY_DEFAULT;
@@ -212,7 +212,7 @@ public class TaskRecordTests extends WindowTestsBase {
     @Test
     public void testBoundsOnModeChangeFreeformToFullscreen() {
         DisplayContent display = mAtm.mRootWindowContainer.getDefaultDisplay();
-        Task stack = new StackBuilder(mRootWindowContainer).setDisplay(display)
+        Task stack = new TaskBuilder(mSupervisor).setDisplay(display).setCreateActivity(true)
                 .setWindowingMode(WINDOWING_MODE_FREEFORM).build();
         Task task = stack.getBottomMostTask();
         task.getRootActivity().setOrientation(SCREEN_ORIENTATION_UNSPECIFIED);
@@ -253,7 +253,7 @@ public class TaskRecordTests extends WindowTestsBase {
         dr.setFixedToUserRotation(FIXED_TO_USER_ROTATION_ENABLED);
         dr.setUserRotation(USER_ROTATION_FREE, ROTATION_0);
 
-        final Task stack = new StackBuilder(mRootWindowContainer)
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true)
                 .setWindowingMode(WINDOWING_MODE_FULLSCREEN).setDisplay(display).build();
         final Task task = stack.getBottomMostTask();
         final ActivityRecord root = task.getTopNonFinishingActivity();
@@ -317,7 +317,7 @@ public class TaskRecordTests extends WindowTestsBase {
         dr.setFixedToUserRotation(FIXED_TO_USER_ROTATION_ENABLED);
         dr.setUserRotation(USER_ROTATION_FREE, ROTATION_0);
 
-        final Task stack = new StackBuilder(mRootWindowContainer)
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true)
                 .setWindowingMode(WINDOWING_MODE_FULLSCREEN).setDisplay(display).build();
         final Task task = stack.getBottomMostTask();
         ActivityRecord root = task.getTopNonFinishingActivity();
@@ -341,7 +341,7 @@ public class TaskRecordTests extends WindowTestsBase {
                 Configuration.ORIENTATION_LANDSCAPE;
         display.onRequestedOverrideConfigurationChanged(
                 display.getRequestedOverrideConfiguration());
-        Task stack = new StackBuilder(mRootWindowContainer)
+        Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true)
                 .setWindowingMode(WINDOWING_MODE_FULLSCREEN).setDisplay(display).build();
         Task task = stack.getBottomMostTask();
         ActivityRecord root = task.getTopNonFinishingActivity();
@@ -497,7 +497,7 @@ public class TaskRecordTests extends WindowTestsBase {
         DisplayInfo displayInfo = new DisplayInfo();
         mAtm.mContext.getDisplay().getDisplayInfo(displayInfo);
         final int displayHeight = displayInfo.logicalHeight;
-        final Task task = new TaskBuilder(mSupervisor).setStack(stack).build();
+        final Task task = new TaskBuilder(mSupervisor).setParentTask(stack).build();
         final Configuration inOutConfig = new Configuration();
         final Configuration parentConfig = new Configuration();
         final int longSide = 1200;
@@ -1029,7 +1029,7 @@ public class TaskRecordTests extends WindowTestsBase {
     }
 
     private Task getTestTask() {
-        final Task stack = new StackBuilder(mRootWindowContainer).build();
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true).build();
         return stack.getBottomMostTask();
     }
 
@@ -1039,7 +1039,7 @@ public class TaskRecordTests extends WindowTestsBase {
         TaskDisplayArea taskDisplayArea = mAtm.mRootWindowContainer.getDefaultTaskDisplayArea();
         Task stack = taskDisplayArea.createStack(windowingMode, ACTIVITY_TYPE_STANDARD,
                 true /* onTop */);
-        Task task = new TaskBuilder(mSupervisor).setStack(stack).build();
+        Task task = new TaskBuilder(mSupervisor).setParentTask(stack).build();
 
         final Configuration parentConfig = stack.getConfiguration();
         parentConfig.windowConfiguration.setAppBounds(parentBounds);
diff --git a/services/tests/wmtests/src/com/android/server/wm/WindowContainerTests.java b/services/tests/wmtests/src/com/android/server/wm/WindowContainerTests.java
index 4163a9a546a0..36f3a21e38f1 100644
--- a/services/tests/wmtests/src/com/android/server/wm/WindowContainerTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/WindowContainerTests.java
@@ -829,7 +829,7 @@ public class WindowContainerTests extends WindowTestsBase {
         final DisplayContent displayContent = createNewDisplay();
         // Do not reparent activity to default display when removing the display.
         doReturn(true).when(displayContent).shouldDestroyContentOnRemove();
-        final ActivityRecord r = new StackBuilder(mWm.mRoot)
+        final ActivityRecord r = new TaskBuilder(mSupervisor).setCreateActivity(true)
                 .setDisplay(displayContent).build().getTopMostActivity();
         // Add a window and make the activity animating so the removal of activity is deferred.
         createWindow(null, TYPE_BASE_APPLICATION, r, "win");
diff --git a/services/tests/wmtests/src/com/android/server/wm/WindowOrganizerTests.java b/services/tests/wmtests/src/com/android/server/wm/WindowOrganizerTests.java
index 46a6a82faba5..38909f6a28d4 100644
--- a/services/tests/wmtests/src/com/android/server/wm/WindowOrganizerTests.java
+++ b/services/tests/wmtests/src/com/android/server/wm/WindowOrganizerTests.java
@@ -290,7 +290,7 @@ public class WindowOrganizerTests extends WindowTestsBase {
     @Test
     public void testTaskTransaction() {
         removeGlobalMinSizeRestriction();
-        final Task stack = new StackBuilder(mWm.mRoot)
+        final Task stack = new TaskBuilder(mSupervisor)
                 .setWindowingMode(WINDOWING_MODE_FREEFORM).build();
         final Task task = stack.getTopMostTask();
         testTransaction(task);
@@ -299,7 +299,7 @@ public class WindowOrganizerTests extends WindowTestsBase {
     @Test
     public void testStackTransaction() {
         removeGlobalMinSizeRestriction();
-        final Task stack = new StackBuilder(mWm.mRoot)
+        final Task stack = new TaskBuilder(mSupervisor)
                 .setWindowingMode(WINDOWING_MODE_FREEFORM).build();
         StackInfo info =
                 mWm.mAtmService.getStackInfo(WINDOWING_MODE_FREEFORM, ACTIVITY_TYPE_STANDARD);
@@ -324,7 +324,7 @@ public class WindowOrganizerTests extends WindowTestsBase {
 
     @Test
     public void testSetWindowingMode() {
-        final Task stack = new StackBuilder(mWm.mRoot)
+        final Task stack = new TaskBuilder(mSupervisor)
                 .setWindowingMode(WINDOWING_MODE_FREEFORM).build();
         testSetWindowingMode(stack);
 
@@ -358,7 +358,7 @@ public class WindowOrganizerTests extends WindowTestsBase {
     @Test
     public void testContainerFocusableChanges() {
         removeGlobalMinSizeRestriction();
-        final Task stack = new StackBuilder(mWm.mRoot)
+        final Task stack = new TaskBuilder(mSupervisor)
                 .setWindowingMode(WINDOWING_MODE_FREEFORM).build();
         final Task task = stack.getTopMostTask();
         WindowContainerTransaction t = new WindowContainerTransaction();
@@ -374,7 +374,7 @@ public class WindowOrganizerTests extends WindowTestsBase {
     @Test
     public void testContainerHiddenChanges() {
         removeGlobalMinSizeRestriction();
-        final Task stack = new StackBuilder(mWm.mRoot)
+        final Task stack = new TaskBuilder(mSupervisor).setCreateActivity(true)
                 .setWindowingMode(WINDOWING_MODE_FREEFORM).build();
         WindowContainerTransaction t = new WindowContainerTransaction();
         assertTrue(stack.shouldBeVisible(null));
@@ -389,7 +389,7 @@ public class WindowOrganizerTests extends WindowTestsBase {
     @Test
     public void testOverrideConfigSize() {
         removeGlobalMinSizeRestriction();
-        final Task stack = new StackBuilder(mWm.mRoot)
+        final Task stack = new TaskBuilder(mSupervisor)
                 .setWindowingMode(WINDOWING_MODE_FREEFORM).build();
         final Task task = stack.getTopMostTask();
         WindowContainerTransaction t = new WindowContainerTransaction();
diff --git a/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java b/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
index 38c4e0a7de02..7daddd8720ab 100644
--- a/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
+++ b/services/tests/wmtests/src/com/android/server/wm/WindowTestsBase.java
@@ -90,6 +90,7 @@ import com.android.server.AttributeCache;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.runner.Description;
+import org.mockito.Mockito;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
@@ -398,22 +399,20 @@ class WindowTestsBase extends SystemServiceTestsBase {
     }
 
     Task createTaskStackOnDisplay(int windowingMode, int activityType, DisplayContent dc) {
-        return new StackBuilder(dc.mWmService.mRoot)
+        return new TaskBuilder(dc.mAtmService.mStackSupervisor)
                 .setDisplay(dc)
                 .setWindowingMode(windowingMode)
                 .setActivityType(activityType)
-                .setCreateActivity(false)
                 .setIntent(new Intent())
                 .build();
     }
 
     Task createTaskStackOnTaskDisplayArea(int windowingMode, int activityType,
             TaskDisplayArea tda) {
-        return new StackBuilder(tda.mWmService.mRoot)
+        return new TaskBuilder(tda.mDisplayContent.mAtmService.mStackSupervisor)
                 .setTaskDisplayArea(tda)
                 .setWindowingMode(windowingMode)
                 .setActivityType(activityType)
-                .setCreateActivity(false)
                 .setIntent(new Intent())
                 .build();
     }
@@ -422,7 +421,7 @@ class WindowTestsBase extends SystemServiceTestsBase {
     Task createTaskInStack(Task stack, int userId) {
         final Task task = new TaskBuilder(stack.mStackSupervisor)
                 .setUserId(userId)
-                .setStack(stack)
+                .setParentTask(stack)
                 .build();
         return task;
     }
@@ -733,7 +732,7 @@ class WindowTestsBase extends SystemServiceTestsBase {
             if (mCreateTask) {
                 mTask = new TaskBuilder(mService.mStackSupervisor)
                         .setComponent(mComponent)
-                        .setStack(mStack).build();
+                        .setParentTask(mStack).build();
             } else if (mTask == null && mStack != null && DisplayContent.alwaysCreateStack(
                     mStack.getWindowingMode(), mStack.getActivityType())) {
                 // The stack can be the task root.
@@ -813,43 +812,51 @@ class WindowTestsBase extends SystemServiceTestsBase {
     protected static class TaskBuilder {
         private final ActivityStackSupervisor mSupervisor;
 
+        private TaskDisplayArea mTaskDisplayArea;
         private ComponentName mComponent;
         private String mPackage;
         private int mFlags = 0;
-        // Task id 0 is reserved in ARC for the home app.
-        private int mTaskId = SystemServicesTestRule.sNextTaskId++;
+        private int mTaskId = -1;
         private int mUserId = 0;
+        private int mWindowingMode = WINDOWING_MODE_UNDEFINED;
+        private int mActivityType = ACTIVITY_TYPE_STANDARD;
+        private ActivityInfo mActivityInfo;
+        private Intent mIntent;
+        private boolean mOnTop = true;
         private IVoiceInteractionSession mVoiceSession;
-        private boolean mCreateStack = true;
 
-        private Task mStack;
-        private TaskDisplayArea mTaskDisplayArea;
+        private boolean mCreateParentTask = false;
+        private Task mParentTask;
+
+        private boolean mCreateActivity = false;
 
         TaskBuilder(ActivityStackSupervisor supervisor) {
             mSupervisor = supervisor;
+            mTaskDisplayArea = mSupervisor.mRootWindowContainer.getDefaultTaskDisplayArea();
         }
 
-        TaskBuilder setComponent(ComponentName component) {
-            mComponent = component;
+        /**
+         * Set the parent {@link DisplayContent} and use the default task display area. Overrides
+         * the task display area, if was set before.
+         */
+        TaskBuilder setDisplay(DisplayContent display) {
+            mTaskDisplayArea = display.getDefaultTaskDisplayArea();
             return this;
         }
 
-        TaskBuilder setPackage(String packageName) {
-            mPackage = packageName;
+        /** Set the parent {@link TaskDisplayArea}. Overrides the display, if was set before. */
+        TaskBuilder setTaskDisplayArea(TaskDisplayArea taskDisplayArea) {
+            mTaskDisplayArea = taskDisplayArea;
             return this;
         }
 
-        /**
-         * Set to {@code true} by default, set to {@code false} to prevent the task from
-         * automatically creating a parent stack.
-         */
-        TaskBuilder setCreateStack(boolean createStack) {
-            mCreateStack = createStack;
+        TaskBuilder setComponent(ComponentName component) {
+            mComponent = component;
             return this;
         }
 
-        TaskBuilder setVoiceSession(IVoiceInteractionSession session) {
-            mVoiceSession = session;
+        TaskBuilder setPackage(String packageName) {
+            mPackage = packageName;
             return this;
         }
 
@@ -868,156 +875,117 @@ class WindowTestsBase extends SystemServiceTestsBase {
             return this;
         }
 
-        TaskBuilder setStack(Task stack) {
-            mStack = stack;
-            return this;
-        }
-
-        TaskBuilder setDisplay(DisplayContent display) {
-            mTaskDisplayArea = display.getDefaultTaskDisplayArea();
-            return this;
-        }
-
-        Task build() {
-            SystemServicesTestRule.checkHoldsLock(mSupervisor.mService.mGlobalLock);
-
-            if (mStack == null && mCreateStack) {
-                TaskDisplayArea displayArea = mTaskDisplayArea != null ? mTaskDisplayArea
-                        : mSupervisor.mRootWindowContainer.getDefaultTaskDisplayArea();
-                mStack = displayArea.createStack(
-                        WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_STANDARD, true /* onTop */);
-                spyOn(mStack);
-            }
-
-            final ActivityInfo aInfo = new ActivityInfo();
-            aInfo.applicationInfo = new ApplicationInfo();
-            aInfo.applicationInfo.packageName = mPackage;
-
-            Intent intent = new Intent();
-            if (mComponent == null) {
-                mComponent = ComponentName.createRelative(DEFAULT_COMPONENT_PACKAGE_NAME,
-                        DEFAULT_COMPONENT_CLASS_NAME);
-            }
-
-            intent.setComponent(mComponent);
-            intent.setFlags(mFlags);
-
-            final Task task = new Task(mSupervisor.mService, mTaskId, aInfo,
-                    intent /*intent*/, mVoiceSession, null /*_voiceInteractor*/,
-                    null /*taskDescription*/, mStack);
-            spyOn(task);
-            task.mUserId = mUserId;
-
-            if (mStack != null) {
-                mStack.moveToFront("test");
-                mStack.addChild(task, true, true);
-            }
-
-            return task;
-        }
-    }
-
-    static class StackBuilder {
-        private final RootWindowContainer mRootWindowContainer;
-        private DisplayContent mDisplay;
-        private TaskDisplayArea mTaskDisplayArea;
-        private int mStackId = -1;
-        private int mWindowingMode = WINDOWING_MODE_UNDEFINED;
-        private int mActivityType = ACTIVITY_TYPE_STANDARD;
-        private boolean mOnTop = true;
-        private boolean mCreateActivity = true;
-        private ActivityInfo mInfo;
-        private Intent mIntent;
-
-        StackBuilder(RootWindowContainer root) {
-            mRootWindowContainer = root;
-            mDisplay = mRootWindowContainer.getDefaultDisplay();
-            mTaskDisplayArea = mDisplay.getDefaultTaskDisplayArea();
-        }
-
-        StackBuilder setWindowingMode(int windowingMode) {
+        TaskBuilder setWindowingMode(int windowingMode) {
             mWindowingMode = windowingMode;
             return this;
         }
 
-        StackBuilder setActivityType(int activityType) {
+        TaskBuilder setActivityType(int activityType) {
             mActivityType = activityType;
             return this;
         }
 
-        StackBuilder setStackId(int stackId) {
-            mStackId = stackId;
+        TaskBuilder setActivityInfo(ActivityInfo info) {
+            mActivityInfo = info;
             return this;
         }
 
-        /**
-         * Set the parent {@link DisplayContent} and use the default task display area. Overrides
-         * the task display area, if was set before.
-         */
-        StackBuilder setDisplay(DisplayContent display) {
-            mDisplay = display;
-            mTaskDisplayArea = mDisplay.getDefaultTaskDisplayArea();
+        TaskBuilder setIntent(Intent intent) {
+            mIntent = intent;
             return this;
         }
 
-        /** Set the parent {@link TaskDisplayArea}. Overrides the display, if was set before. */
-        StackBuilder setTaskDisplayArea(TaskDisplayArea taskDisplayArea) {
-            mTaskDisplayArea = taskDisplayArea;
-            mDisplay = mTaskDisplayArea.mDisplayContent;
+        TaskBuilder setOnTop(boolean onTop) {
+            mOnTop = onTop;
             return this;
         }
 
-        StackBuilder setOnTop(boolean onTop) {
-            mOnTop = onTop;
+        TaskBuilder setVoiceSession(IVoiceInteractionSession session) {
+            mVoiceSession = session;
             return this;
         }
 
-        StackBuilder setCreateActivity(boolean createActivity) {
-            mCreateActivity = createActivity;
+        TaskBuilder setCreateParentTask(boolean createParentTask) {
+            mCreateParentTask = createParentTask;
             return this;
         }
 
-        StackBuilder setActivityInfo(ActivityInfo info) {
-            mInfo = info;
+        TaskBuilder setParentTask(Task parentTask) {
+            mParentTask = parentTask;
             return this;
         }
 
-        StackBuilder setIntent(Intent intent) {
-            mIntent = intent;
+        TaskBuilder setCreateActivity(boolean createActivity) {
+            mCreateActivity = createActivity;
             return this;
         }
 
         Task build() {
-            SystemServicesTestRule.checkHoldsLock(mRootWindowContainer.mWmService.mGlobalLock);
+            SystemServicesTestRule.checkHoldsLock(mSupervisor.mService.mGlobalLock);
+
+            // Create parent task.
+            if (mParentTask == null && mCreateParentTask) {
+                mParentTask = mTaskDisplayArea.createStack(
+                        WINDOWING_MODE_FULLSCREEN, ACTIVITY_TYPE_STANDARD, true /* onTop */);
+            }
+            if (mParentTask != null && !Mockito.mockingDetails(mParentTask).isSpy()) {
+                spyOn(mParentTask);
+            }
+
+            // Create task.
+            if (mActivityInfo == null) {
+                mActivityInfo = new ActivityInfo();
+                mActivityInfo.applicationInfo = new ApplicationInfo();
+                mActivityInfo.applicationInfo.packageName = mPackage;
+            }
 
-            final int stackId = mStackId >= 0 ? mStackId : mTaskDisplayArea.getNextStackId();
-            final Task stack = mTaskDisplayArea.createStackUnchecked(
-                    mWindowingMode, mActivityType, stackId, mOnTop, mInfo, mIntent,
-                    false /* createdByOrganizer */);
-            final ActivityStackSupervisor supervisor = mRootWindowContainer.mStackSupervisor;
+            if (mIntent == null) {
+                mIntent = new Intent();
+                if (mComponent == null) {
+                    mComponent = ComponentName.createRelative(DEFAULT_COMPONENT_PACKAGE_NAME,
+                            DEFAULT_COMPONENT_CLASS_NAME);
+                }
+                mIntent.setComponent(mComponent);
+                mIntent.setFlags(mFlags);
+            }
 
+            Task task;
+            final int taskId = mTaskId >= 0 ? mTaskId : mTaskDisplayArea.getNextStackId();
+            if (mParentTask == null) {
+                task = mTaskDisplayArea.createStackUnchecked(
+                        mWindowingMode, mActivityType, taskId, mOnTop, mActivityInfo,
+                        mIntent, false /* createdByOrganizer */);
+            } else {
+                task = new Task(mSupervisor.mService, taskId, mActivityInfo,
+                        mIntent /*intent*/, mVoiceSession, null /*_voiceInteractor*/,
+                        null /*taskDescription*/, mParentTask);
+                mParentTask.moveToFront("build-task");
+                mParentTask.addChild(task, true, true);
+            }
+            spyOn(task);
+            task.mUserId = mUserId;
+            Task rootTask = task.getRootTask();
+            doNothing().when(rootTask).startActivityLocked(
+                    any(), any(), anyBoolean(), anyBoolean(), any());
+
+            // Create child task with activity.
             if (mCreateActivity) {
-                new ActivityBuilder(supervisor.mService)
+                new ActivityBuilder(mSupervisor.mService)
                         .setCreateTask(true)
-                        .setStack(stack)
+                        .setStack(task)
                         .build();
                 if (mOnTop) {
                     // We move the task to front again in order to regain focus after activity
-                    // added to the stack. Or {@link DisplayContent#mPreferredTopFocusableStack}
+                    // added to the stack. Or {@link TaskDisplayArea#mPreferredTopFocusableStack}
                     // could be other stacks (e.g. home stack).
-                    stack.moveToFront("createActivityStack");
+                    task.moveToFront("createActivityTask");
                 } else {
-                    stack.moveToBack("createActivityStack", null);
+                    task.moveToBack("createActivityTask", null);
                 }
             }
-            spyOn(stack);
-
-            doNothing().when(stack).startActivityLocked(
-                    any(), any(), anyBoolean(), anyBoolean(), any());
 
-            return stack;
+            return task;
         }
-
     }
 
     static class TestSplitOrganizer extends ITaskOrganizer.Stub {