Introduce ViewRoot forwarding input/view events to native

ui/android/display_android_manager.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_DISPLAY_ANDROID_MANAGER_H_
 #define UI_ANDROID_DISPLAY_ANDROID_MANAGER_H_
 
 #include <jni.h>
 
 #include "base/android/jni_android.h"
 #include "base/macros.h"
+#include "ui/android/ui_android_export.h"
 #include "ui/display/screen_base.h"
 
 namespace ui {
 
-class DisplayAndroidManager : public display::ScreenBase {
+class UI_ANDROID_EXPORT DisplayAndroidManager : public display::ScreenBase {
  public:
   ~DisplayAndroidManager() override;
 
+  // Prefer using |Screen::GetScreen()|. Only use this to avoid casting.
+  static DisplayAndroidManager* GetInstance();
+
+  // This method is needed since NativeWindow is not a NativeView on Android.
+  display::Display GetDisplayNearestWindowAndroid(
+      gfx::NativeWindow window) const;
+
   // Screen interface.
 
   display::Display GetDisplayNearestWindow(gfx::NativeView view) const override;
   display::Display GetDisplayNearestPoint(
       const gfx::Point& point) const override;
   display::Display GetDisplayMatching(
       const gfx::Rect& match_rect) const override;
 
   // Methods called from Java.
 
@@ skipping 20 matching lines @@
   DisplayAndroidManager();
 
   int primary_display_id_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(DisplayAndroidManager);
 };
 
 }  // namespace ui
 
 #endif  // UI_ANDROID_DISPLAY_ANDROID_MANAGER_H_