Changing A11yManagerService to respond to user switching from Lifecycle instead of Intents.

This shrinks the window in which AMS holds an incorrect userId to near non-existence, preventing most if not all user-incurred bugs regarding wrong userIds.

Test: atest AccessibilityManagerServiceTest
Flag: com.android.server.accessibility.manager_lifecycle_user_change
Bug: 393626471
Change-Id: I9a8d21a7449da9f27cbf283584e0960d8c79d37e

2 files changed, 28 insertions, 1 deletions

diff --git a/services/accessibility/accessibility.aconfig b/services/accessibility/accessibility.aconfig
index 35db3c6f0a6d..a133131a1d3f 100644
--- a/services/accessibility/accessibility.aconfig
+++ b/services/accessibility/accessibility.aconfig
@@ -223,6 +223,16 @@ flag {
 }
 
 flag {
+    name: "manager_lifecycle_user_change"
+    namespace: "accessibility"
+    description: "Use A11yManagerService's Lifecycle to change users, instead of listening for user changed events."
+    bug: "393626471"
+    metadata {
+        purpose: PURPOSE_BUGFIX
+    }
+}
+
+flag {
     name: "motion_event_injector_cancel_fix"
     namespace: "accessibility"
     description: "Fix the ACTION_CANCEL logic used in MotionEventInjector to avoid InputDispatcher inconsistency"
diff --git a/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java b/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java
index 703e37fad5ad..69ea12d86d47 100644
--- a/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java
+++ b/services/accessibility/java/com/android/server/accessibility/AccessibilityManagerService.java
@@ -500,6 +500,12 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub
             mService = new AccessibilityManagerService(context);
         }
 
+        @VisibleForTesting
+        public Lifecycle(Context context, AccessibilityManagerService service) {
+            super(context);
+            mService = service;
+        }
+
         @Override
         public void onStart() {
             LocalServices.addService(AccessibilityManagerInternal.class,
@@ -511,6 +517,15 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub
         public void onBootPhase(int phase) {
             mService.onBootPhase(phase);
         }
+
+        @Override
+        public void onUserSwitching(@androidx.annotation.Nullable TargetUser from,
+                @androidx.annotation.NonNull TargetUser to) {
+            super.onUserSwitching(from, to);
+            if (Flags.managerLifecycleUserChange()) {
+                mService.switchUser(to.getUserIdentifier());
+            }
+        }
     }
 
     private InputManager.KeyGestureEventHandler mKeyGestureEventHandler =
@@ -1055,7 +1070,9 @@ public class AccessibilityManagerService extends IAccessibilityManager.Stub
 
                 String action = intent.getAction();
                 if (Intent.ACTION_USER_SWITCHED.equals(action)) {
-                    switchUser(intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0));
+                    if (!Flags.managerLifecycleUserChange()) {
+                        switchUser(intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0));
+                    }
                 } else if (Intent.ACTION_USER_UNLOCKED.equals(action)) {
                     unlockUser(intent.getIntExtra(Intent.EXTRA_USER_HANDLE, 0));
                 } else if (Intent.ACTION_USER_REMOVED.equals(action)) {