diff --git a/services/core/java/com/android/server/wm/AppWindowToken.java b/services/core/java/com/android/server/wm/AppWindowToken.java
index 44d7948b12b62..32b722126b8d8 100644
--- a/services/core/java/com/android/server/wm/AppWindowToken.java
+++ b/services/core/java/com/android/server/wm/AppWindowToken.java
@@ -645,8 +645,7 @@ class AppWindowToken extends WindowToken implements WindowManagerService.AppFree
         boolean destroyedSomething = false;
 
         // Copying to a different list as multiple children can be removed.
-        // TODO: Not sure why this is needed.
-        final LinkedList<WindowState> children = new LinkedList<>(mChildren);
+        final ArrayList<WindowState> children = new ArrayList<>(mChildren);
         for (int i = children.size() - 1; i >= 0; i--) {
             final WindowState win = children.get(i);
             destroyedSomething |= win.destroySurface(cleanupOnResume, mAppStopped);
diff --git a/services/core/java/com/android/server/wm/WindowState.java b/services/core/java/com/android/server/wm/WindowState.java
index 0e025dc8a96db..f541752aee6ed 100644
--- a/services/core/java/com/android/server/wm/WindowState.java
+++ b/services/core/java/com/android/server/wm/WindowState.java
@@ -2642,8 +2642,11 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
 
     boolean destroySurface(boolean cleanupOnResume, boolean appStopped) {
         boolean destroyedSomething = false;
-        for (int i = mChildren.size() - 1; i >= 0; --i) {
-            final WindowState c = mChildren.get(i);
+
+        // Copying to a different list as multiple children can be removed.
+        final ArrayList<WindowState> childWindows = new ArrayList<>(mChildren);
+        for (int i = childWindows.size() - 1; i >= 0; --i) {
+            final WindowState c = childWindows.get(i);
             destroyedSomething |= c.destroySurface(cleanupOnResume, appStopped);
         }
 
@@ -3873,8 +3876,7 @@ class WindowState extends WindowContainer<WindowState> implements WindowManagerP
 
         if (!mChildren.isEmpty()) {
             // Copying to a different list as multiple children can be removed.
-            // TODO: Not sure if we really need to copy this into a different list.
-            final LinkedList<WindowState> childWindows = new LinkedList(mChildren);
+            final ArrayList<WindowState> childWindows = new ArrayList<>(mChildren);
             for (int i = childWindows.size() - 1; i >= 0; i--) {
                 childWindows.get(i).onExitAnimationDone();
             }