Make WindowAndroid a ViewAndroid

ui/android/window_android.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_ANDROID_WINDOW_ANDROID_H_
 #define UI_ANDROID_WINDOW_ANDROID_H_
 
 #include <jni.h>
 #include <string>
 #include <vector>
 
 #include "base/android/jni_weak_ref.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "ui/android/ui_android_export.h"
+#include "ui/android/view_android.h"
 #include "ui/gfx/geometry/vector2d_f.h"
 
 namespace ui {
 
 class WindowAndroidCompositor;
 class WindowAndroidObserver;
 
 // Android implementation of the activity window.
-class UI_ANDROID_EXPORT WindowAndroid {
+// WindowAndroid is also the root of a ViewAndroid tree.
+class UI_ANDROID_EXPORT WindowAndroid : public ViewAndroid {
  public:
   WindowAndroid(JNIEnv* env, jobject obj);
 
   void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
 
   base::android::ScopedJavaLocalRef<jobject> GetJavaObject();
 
   static bool RegisterWindowAndroid(JNIEnv* env);
 
   // The content offset is used to translate snapshots to the correct part of
@@ skipping 37 matching lines @@
   // Return whether the specified Android permission can be requested by Chrome.
   bool CanRequestPermission(const std::string& permission);
 
   static WindowAndroid* createForTesting();
   void StartDragAndDrop(
       const base::android::JavaRef<jobject>& jview_android_delegate,
       const base::android::JavaRef<jstring>& jtext,
       const base::android::JavaRef<jobject>& jimage);
 
  private:
-  ~WindowAndroid();
+  ~WindowAndroid() override;
+
+  // ViewAndroid overrides.
+  WindowAndroid* GetWindowAndroid() const override;
 
   base::android::ScopedJavaGlobalRef<jobject> java_window_;
   gfx::Vector2dF content_offset_;
   WindowAndroidCompositor* compositor_;
 
   base::ObserverList<WindowAndroidObserver> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowAndroid);
 };
 
 }  // namespace ui
 
 #endif  // UI_ANDROID_WINDOW_ANDROID_H_