Replace mPendingRemove with hierarchy deferred removal

To eliminate the global list and simplify the path of surface placement.

Bug: 163976519
Test: CtsActivityManagerDeviceTestCases
Change-Id: I801606acf4689a4c950e5d21ffe1e4894fe855f9

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

@@ -983,29 +983,6 @@ class RootWindowContainer extends WindowContainer<DisplayContent>
             mWmService.checkDrawnWindowsLocked();
         }
 
-        final int N = mWmService.mPendingRemove.size();
-        if (N > 0) {
-            if (mWmService.mPendingRemoveTmp.length < N) {
-                mWmService.mPendingRemoveTmp = new WindowState[N + 10];
-            }
-            mWmService.mPendingRemove.toArray(mWmService.mPendingRemoveTmp);
-            mWmService.mPendingRemove.clear();
-            ArrayList<DisplayContent> displayList = new ArrayList();
-            for (i = 0; i < N; i++) {
-                final WindowState w = mWmService.mPendingRemoveTmp[i];
-                w.removeImmediately();
-                final DisplayContent displayContent = w.getDisplayContent();
-                if (displayContent != null && !displayList.contains(displayContent)) {
-                    displayList.add(displayContent);
-                }
-            }
-
-            for (int j = displayList.size() - 1; j >= 0; --j) {
-                final DisplayContent dc = displayList.get(j);
-                dc.assignWindowLayers(true /*setLayoutNeeded*/);
-            }
-        }
-
         forAllDisplays(dc -> {
             dc.getInputMonitor().updateInputWindowsLw(true /*force*/);
             dc.updateSystemGestureExclusion();

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

@@ -221,7 +221,6 @@ import android.util.DisplayMetrics;
 import android.util.EventLog;
 import android.util.MergedConfiguration;
 import android.util.Slog;
-import android.util.SparseArray;
 import android.util.SparseBooleanArray;
 import android.util.TimeUtils;
 import android.util.TypedValue;
@@ -586,20 +585,6 @@ public class WindowManagerService extends IWindowManager.Stub
      */
     final ArrayList<WindowState> mResizingWindows = new ArrayList<>();
 
-    /**
-     * Windows whose animations have ended and now must be removed.
-     */
-    final ArrayList<WindowState> mPendingRemove = new ArrayList<>();
-
-    /**
-     * Used when processing mPendingRemove to avoid working on the original array.
-     */
-    WindowState[] mPendingRemoveTmp = new WindowState[20];
-
-    // TODO: use WindowProcessController once go/wm-unified is done.
-    /** Mapping of process pids to configurations */
-    final SparseArray<Configuration> mProcessConfigurations = new SparseArray<>();
-
     /**
      * Windows whose surface should be destroyed.
      */
@@ -2035,7 +2020,6 @@ public class WindowManagerService extends IWindowManager.Stub
             dc.mWinRemovedSinceNullFocus.add(win);
         }
         mEmbeddedWindowController.onWindowRemoved(win);
-        mPendingRemove.remove(win);
         mResizingWindows.remove(win);
         updateNonSystemOverlayWindowsVisibilityIfNeeded(win, false /* surfaceShown */);
         mWindowsChanged = true;
@@ -6352,23 +6336,6 @@ public class WindowManagerService extends IWindowManager.Stub
                 }
             }
         }
-        if (mPendingRemove.size() > 0) {
-            pw.println();
-            pw.println("  Remove pending for:");
-            for (int i=mPendingRemove.size()-1; i>=0; i--) {
-                WindowState w = mPendingRemove.get(i);
-                if (windows == null || windows.contains(w)) {
-                    pw.print("  Remove #"); pw.print(i); pw.print(' ');
-                            pw.print(w);
-                    if (dumpAll) {
-                        pw.println(":");
-                        w.dump(pw, "    ", true);
-                    } else {
-                        pw.println();
-                    }
-                }
-            }
-        }
         if (mForceRemoves != null && mForceRemoves.size() > 0) {
             pw.println();
             pw.println("  Windows force removing:");

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

@@ -4831,15 +4831,20 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
             if (hasSurface) {
                 mWmService.mDestroySurface.add(this);
             }
-            if (mRemoveOnExit) {
-                mWmService.mPendingRemove.add(this);
-                mRemoveOnExit = false;
-            }
         }
         mAnimatingExit = false;
         getDisplayContent().mWallpaperController.hideWallpapers(this);
     }
 
+    @Override
+    boolean handleCompleteDeferredRemoval() {
+        if (mRemoveOnExit) {
+            mRemoveOnExit = false;
+            removeImmediately();
+        }
+        return super.handleCompleteDeferredRemoval();
+    }
+
     boolean clearAnimatingFlags() {
         boolean didSomething = false;
         // We don't want to clear it out for windows that get replaced, because the