Revert "Introduce ViewRoot forwarding input/view events to native"

ui/android/view_client.h

-// Copyright 2016 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_VIEW_CLIENT_H_
-#define UI_ANDROID_VIEW_CLIENT_H_
-
-#include "ui/android/ui_android_export.h"
-
-namespace ui {
-
-// Client interface used to forward events from Java to native views.
-// Calls are dispatched to its children along the hierarchy of ViewAndroid.
-// Use bool return type to stop propagating the call i.e. overriden method
-// should return true to indicate that the event was handled and stop
-// the processing.
-class UI_ANDROID_EXPORT ViewClient {
- public:
-  virtual void OnPhysicalBackingSizeChanged(int width, int height);
-};
-
-}  // namespace ui
-
-#endif  // UI_ANDROID_VIEW_CLIENT_H_