Restore direct display children to display layer

This undoes I78d4832b0ff7623684fc22fe1f464a02a1d91477.
Because now a display always has a real DisplayArea to provide
windowing layer (created by DisplayAreaPolicyBuilder).

Old:
 RootWrapper (DisplayContent#mSurfaceControl)
   > WindowingLayer (pure layer, not a WindowContainer)
     >> Child of display

 The surface of direct child under display uses WindowingLayer
 as parent.

Now:
 Display (DisplayContent#mSurfaceControl)
   > WindowingLayer (DisplayArea)
     >> Child of WindowingLayer

 The surface of direct child under display uses display as parent.
 Because the surface hierarchy is consistent with window hierarchy.

Bug: 326975721
Bug: 266243524
Test: AccessibilityOverlayTest#testA11yServiceShowsOverlayOnVirtualDisplay_shouldAppear
Change-Id: I7a1d09eb566e29e532d56627a9955692b55a5682

2 files changed, 0 insertions, 11 deletions

diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index ce44bb5d5f36..3e8adc9dc5cd 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -5448,11 +5448,6 @@ class DisplayContent extends RootDisplayArea implements WindowManagerPolicy.Disp
             return b;
         }
 
-        // WARNING: it says `mSurfaceControl` below, but this CHANGES meaning after construction!
-        // DisplayAreas are added in `configureSurface()` *before* `mSurfaceControl` gets replaced
-        // with a wrapper or magnification surface so they end up in the right place; however,
-        // anything added or reparented to "the display" *afterwards* needs to be reparented to
-        // `getWindowinglayer()` (unless it's an overlay DisplayArea).
         return b.setName(child.getName())
                 .setParent(mSurfaceControl);
     }
diff --git a/services/core/java/com/android/server/wm/Transition.java b/services/core/java/com/android/server/wm/Transition.java
index 6d8b03020561..66c2e537ba9b 100644
--- a/services/core/java/com/android/server/wm/Transition.java
+++ b/services/core/java/com/android/server/wm/Transition.java
@@ -2542,12 +2542,6 @@ class Transition implements BLASTSyncEngine.TransactionReadyListener {
             // DisplayContent is the "root", so we reinterpret it's wc as the window layer
             // making the parent surface the displaycontent's surface.
             return wc.getSurfaceControl();
-        } else if (wc.getParent().asDisplayContent() != null) {
-            // DisplayContent is kinda split into 2 pieces, the "real root" and the
-            // "windowing layer". So if the parent of the window is DC, then it really belongs on
-            // the windowing layer (unless it's an overlay display area, but those can't be in
-            // transitions anyways).
-            return wc.getParent().asDisplayContent().getWindowingLayer();
         }
         return wc.getParent().getSurfaceControl();
     }