Update tray when a window is closed (and focus didn't change) (#1723)

Author: MortimerGoro

app/src/common/shared/org/mozilla/vrbrowser/VRBrowserActivity.java

@@ -270,6 +270,11 @@ public void onWindowBorderChanged(@NonNull WindowWidget aChangeWindow) {
             public void onWindowsMoved() {
                 updateWidget(mTray);
             }
+
+            @Override
+            public void onWindowClosed() {
+                updateWidget(mTray);
+            }
         });
 
         // Create Browser navigation widget

app/src/common/shared/org/mozilla/vrbrowser/ui/widgets/Windows.java

@@ -89,6 +89,7 @@ public interface Delegate {
         void onFocusedWindowChanged(@NonNull WindowWidget aFocusedWindow, @Nullable WindowWidget aPrevFocusedWindow);
         void onWindowBorderChanged(@NonNull WindowWidget aChangeWindow);
         void onWindowsMoved();
+        void onWindowClosed();
     }
 
     public Windows(Context aContext) {
@@ -276,6 +277,9 @@ public void closeWindow(@NonNull WindowWidget aWindow) {
         }
 
         updateViews();
+        if (mDelegate != null) {
+            mDelegate.onWindowClosed();
+        }
     }
 
     public void moveWindowRight(@NonNull WindowWidget aWindow) {