Reland of Android: support multiple displays on C++ side

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/display/display.h"
 #include "ui/gfx/geometry/vector2d_f.h"
 
+namespace display {
+class DisplayAndroidManager;
+}
+
 namespace ui {
 
 class WindowAndroidCompositor;
 class WindowAndroidObserver;
 
 // Android implementation of the activity window.
 // WindowAndroid is also the root of a ViewAndroid tree.
 class UI_ANDROID_EXPORT WindowAndroid : public ViewAndroid {
  public:
-  WindowAndroid(JNIEnv* env, jobject obj);
+  WindowAndroid(JNIEnv* env, jobject obj, int display_id);
 
   void Destroy(JNIEnv* env, const base::android::JavaParamRef<jobject>& obj);
 
   base::android::ScopedJavaLocalRef<jobject> GetJavaObject();
 
   static bool RegisterWindowAndroid(JNIEnv* env);
 
   // The content offset in CSS pixels. It is used together with device scale
   // factor to translate snapshots to the correct part of the window.
   void set_content_offset(const gfx::Vector2dF& content_offset) {
@@ skipping 32 matching lines @@
 
   // Return whether the specified Android permission is granted.
   bool HasPermission(const std::string& permission);
   // Return whether the specified Android permission can be requested by Chrome.
   bool CanRequestPermission(const std::string& permission);
 
   static WindowAndroid* CreateForTesting();
   void DestroyForTesting();
 
  private:
+  friend class display::DisplayAndroidManager;
+
   ~WindowAndroid() override;
 
   // ViewAndroid overrides.
   WindowAndroid* GetWindowAndroid() const override;
 
+  // The ID of the display that this window belongs to.
+  int display_id() const { return display_id_; }
+
   base::android::ScopedJavaGlobalRef<jobject> java_window_;
+  int display_id_;
   gfx::Vector2dF content_offset_;
   WindowAndroidCompositor* compositor_;
 
   base::ObserverList<WindowAndroidObserver> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowAndroid);
 };
 
 }  // namespace ui
 
 #endif  // UI_ANDROID_WINDOW_ANDROID_H_