Clear transitions for app windows display change.

This prevents unwanted animations from running for windows on the new
display that are no longer relevant.

Bug: 128449959

Test: manual - launch activity with options moving between virtual and
default display, atest WmTests
Change-Id: I2fbd7ab5240c626f3bce82c930001a6a2c6ed6a9

services/core/java/com/android/server/wm/AppWindowToken.java

@@ -1322,7 +1322,9 @@ class AppWindowToken extends WindowToken implements WindowManagerService.AppFree
         if (prevDc == null || prevDc == mDisplayContent) {
             return;
         }
-        if (prevDc.mChangingApps.contains(this)) {
+
+        prevDc.mOpeningApps.remove(this);
+        if (prevDc.mChangingApps.remove(this)) {
             // This gets called *after* the AppWindowToken has been reparented to the new display.
             // That reparenting resulted in this window changing modes (eg. FREEFORM -> FULLSCREEN),
             // so this token is now "frozen" while waiting for the animation to start on prevDc
@@ -1331,6 +1333,8 @@ class AppWindowToken extends WindowToken implements WindowManagerService.AppFree
             // so we need to cancel the change transition here.
             clearChangeLeash(getPendingTransaction(), true /* cancel */);
         }
+        prevDc.mClosingApps.remove(this);
+
         if (prevDc.mFocusedApp == this) {
             prevDc.setFocusedApp(null);
             final TaskStack stack = dc.getTopStack();
@@ -3216,16 +3220,6 @@ class AppWindowToken extends WindowToken implements WindowManagerService.AppFree
                 true /* topToBottom */);
     }
 
-    void removeFromPendingTransition() {
-        if (isWaitingForTransitionStart() && mDisplayContent != null) {
-            mDisplayContent.mOpeningApps.remove(this);
-            if (mDisplayContent.mChangingApps.remove(this)) {
-                clearChangeLeash(getPendingTransaction(), true /* cancel */);
-            }
-            mDisplayContent.mClosingApps.remove(this);
-        }
-    }
-
     private void updateColorTransform() {
         if (mSurfaceControl != null && mLastAppSaturationInfo != null) {
             getPendingTransaction().setColorTransform(mSurfaceControl,

services/core/java/com/android/server/wm/DisplayContent.java

@@ -2377,9 +2377,6 @@ class DisplayContent extends WindowContainer<DisplayContent.DisplayChildWindowCo
                     + " to its current displayId=" + mDisplayId);
         }
 
-        // Clean up all pending transitions when stack reparent to another display.
-        stack.forAllAppWindows(AppWindowToken::removeFromPendingTransition);
-
         prevDc.mTaskStackContainers.removeChild(stack);
         mTaskStackContainers.addStackToDisplay(stack, onTop);
     }