aura: Support SurfaceDestroyed() on Android

ui/platform_window/platform_window_delegate.h

 // Copyright 2014 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_PLATFORM_WINDOW_PLATFORM_WINDOW_DELEGATE_H_
 #define UI_PLATFORM_WINDOW_PLATFORM_WINDOW_DELEGATE_H_
 
 #include "ui/gfx/native_widget_types.h"
 
 namespace gfx {
@@ skipping 28 matching lines @@
   virtual void OnCloseRequest() = 0;
   virtual void OnClosed() = 0;
 
   virtual void OnWindowStateChanged(PlatformWindowState new_state) = 0;
 
   virtual void OnLostCapture() = 0;
 
   virtual void OnAcceleratedWidgetAvailable(gfx::AcceleratedWidget widget,
                                             float device_pixel_ratio) = 0;
 
+  // Notifies the delegate that the widget cannot be used anymore until
+  // a new widget is made available through OnAcceleratedWidgetAvailable().
+  virtual void OnAcceleratedWidgetDestroyed() = 0;
+
   virtual void OnActivationChanged(bool active) = 0;
 };
 
 }  // namespace ui
 
 #endif  // UI_PLATFORM_WINDOW_PLATFORM_WINDOW_DELEGATE_H_