Adding compositor callbacks to RenderWidgetHostViewAndroid

ui/base/android/window_android_observer.h

+// Copyright 2013 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_BASE_ANDROID_WINDOW_ANDROID_OBSERVER_H_
+#define UI_BASE_ANDROID_WINDOW_ANDROID_OBSERVER_H_
+
+#include "ui/base/ui_export.h"
+
+namespace ui {
+
+class UI_EXPORT WindowAndroidObserver {
+ public:
+  virtual void OnCompositingDidCommit() = 0;
+  virtual void OnAttachCompositor() = 0;
+  virtual void OnDetachCompositor() = 0;
+
+ protected:
+  virtual ~WindowAndroidObserver() {}
+};
+
+}  // namespace ui
+
+#endif  // UI_BASE_ANDROID_WINDOW_ANDROID_OBSERVER_H_