Android: Don't destroy LayerTreeHost when Surface goes away

ui/android/resources/ui_resource_android.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_ANDROID_RESOURCES_UI_RESOURCE_ANDROID_H_
 #define UI_ANDROID_RESOURCES_UI_RESOURCE_ANDROID_H_
 
 #include "base/basictypes.h"
 #include "cc/resources/ui_resource_bitmap.h"
 #include "third_party/skia/include/core/SkBitmap.h"
@@ skipping 10 matching lines @@
   static scoped_ptr<UIResourceAndroid> CreateFromJavaBitmap(
       ui::UIResourceProvider* provider,
       const gfx::JavaBitmap& java_bitmap);
 
   ~UIResourceAndroid() override;
 
   // cc::UIResourceClient implementation.
   cc::UIResourceBitmap GetBitmap(cc::UIResourceId uid,
                                  bool resource_lost) override;
 
-  // ui::UIResourceClientAndroid implementation.
-  void UIResourceIsInvalid() override;
-
   cc::UIResourceId id();
 
  private:
   UIResourceAndroid(ui::UIResourceProvider* provider, const SkBitmap& skbitmap);
 
   ui::UIResourceProvider* provider_;
   SkBitmap bitmap_;
   cc::UIResourceId id_;
 
   DISALLOW_COPY_AND_ASSIGN(UIResourceAndroid);
 };
 
 }  // namespace ui
 
 #endif  // UI_ANDROID_RESOURCES_UI_RESOURCE_ANDROID_H_