Add null check for view holder before closing

NullPointerExceptions thrown in tests when attempting to close a null view holder in DesktopModeWindowDecoration#close

Bug: 403310239 
Flag: com.android.window.flags.enable_desktop_windowing_mode
Test: run test
Change-Id: If28aa3e0e193efd50d840a5190917e825d264222

1 files changed, 4 insertions, 2 deletions

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
index bcf9396ff0c1..989550c60c0d 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/windowdecor/DesktopModeWindowDecoration.java
@@ -1756,8 +1756,10 @@ public class DesktopModeWindowDecoration extends WindowDecoration<WindowDecorLin
         mExclusionRegionListener.onExclusionRegionDismissed(mTaskInfo.taskId);
         disposeResizeVeil();
         disposeStatusBarInputLayer();
-        mWindowDecorViewHolder.close();
-        mWindowDecorViewHolder = null;
+        if (mWindowDecorViewHolder != null) {
+            mWindowDecorViewHolder.close();
+            mWindowDecorViewHolder = null;
+        }
         if (canEnterDesktopMode(mContext) && isEducationEnabled()) {
             notifyNoCaptionHandle();
         }