Ensure that mask layer is of the same size as the owning layer.

ui/views/bubble/tray_bubble_view.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_BUBBLE_TRAY_BUBBLE_VIEW_H_
 #define UI_VIEWS_BUBBLE_TRAY_BUBBLE_VIEW_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 127 matching lines @@
   void OnMouseEntered(const ui::MouseEvent& event) override;
   void OnMouseExited(const ui::MouseEvent& event) override;
   void GetAccessibleNodeData(ui::AXNodeData* node_data) override;
 
   // Overridden from MouseWatcherListener
   void MouseMovedOutOfHost() override;
 
  protected:
   // Overridden from views::BubbleDialogDelegateView.
   int GetDialogButtons() const override;
+  void SizeToContents() override;
 
   // Overridden from views::View.
   void ChildPreferredSizeChanged(View* child) override;
   void ViewHierarchyChanged(
       const ViewHierarchyChangedDetails& details) override;
 
  private:
   InitParams params_;
   BoxLayout* layout_;
   Delegate* delegate_;
@@ skipping 11 matching lines @@
 
   // Used to find any mouse movements.
   std::unique_ptr<MouseWatcher> mouse_watcher_;
 
   DISALLOW_COPY_AND_ASSIGN(TrayBubbleView);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_BUBBLE_TRAY_BUBBLE_VIEW_H_