Introduce ViewRoot to forward input/view events to native

content/browser/renderer_host/render_widget_host_view_android.h

Index: content/browser/renderer_host/render_widget_host_view_android.h
diff --git a/content/browser/renderer_host/render_widget_host_view_android.h b/content/browser/renderer_host/render_widget_host_view_android.h
index d29a0a9d0ff96b9b2c67a2d7f66287556797697f..84ce109b70d2fd5a139e93222315644fb67d0255 100644
--- a/content/browser/renderer_host/render_widget_host_view_android.h
+++ b/content/browser/renderer_host/render_widget_host_view_android.h
@@ -32,6 +32,7 @@
 #include "gpu/command_buffer/common/mailbox.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/android/view_android.h"
+#include "ui/android/view_client.h"
 #include "ui/android/window_android_observer.h"
 #include "ui/events/android/motion_event_android.h"
 #include "ui/events/gesture_detection/filtered_gesture_provider.h"
@@ -65,6 +66,7 @@ struct NativeWebKeyboardEvent;
 class CONTENT_EXPORT RenderWidgetHostViewAndroid
     : public RenderWidgetHostViewBase,
       public ui::GestureProviderClient,
+      public ui::ViewClient,
       public ui::WindowAndroidObserver,
       public DelegatedFrameEvictorClient,
       public StylusTextSelectorClient,
@@ -157,6 +159,9 @@ class CONTENT_EXPORT RenderWidgetHostViewAndroid
   void OnDidNavigateMainFrameToNewPage() override;
   void SetNeedsBeginFrames(bool needs_begin_frames) override;
 
+  // ui::ViewClient implementation.
+  void OnPhysicalBackingSizeChanged(int width, int height) override;
+
   // ui::GestureProviderClient implementation.
   void OnGestureEvent(const ui::GestureEventData& gesture) override;