Implement hit tests/client area.

ui/views/mus/mus_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_VIEWS_MUS_MUS_CLIENT_H_
 #define UI_VIEWS_MUS_MUS_CLIENT_H_
 
 #include <string>
 
 #include "base/macros.h"
@@ skipping 19 matching lines @@
 class Connector;
 class Identity;
 }
 
 namespace wm {
 class WMState;
 }
 
 namespace views {
 
+class MusClientObserver;
 class ScreenMus;
 
 namespace internal {
 class NativeWidgetDelegate;
 }
 
 namespace test {
 class MusClientTestApi;
 }
 
@@ skipping 22 matching lines @@
   aura::WindowTreeClient* window_tree_client() {
     return window_tree_client_.get();
   }
 
   // Creates DesktopNativeWidgetAura with DesktopWindowTreeHostMus. This is
   // set as the factory function used for creating NativeWidgets when a
   //  NativeWidget has not been explicitly set.
   NativeWidget* CreateNativeWidget(const Widget::InitParams& init_params,
                                    internal::NativeWidgetDelegate* delegate);
 
+  void AddObserver(MusClientObserver* observer);
+  void RemoveObserver(MusClientObserver* observer);
+
  private:
   friend class AuraInit;
   friend class test::MusClientTestApi;
 
   MusClient(
       service_manager::Connector* connector,
       const service_manager::Identity& identity,
       scoped_refptr<base::SingleThreadTaskRunner> io_task_runner = nullptr);
 
   // aura::WindowTreeClientDelegate:
@@ skipping 12 matching lines @@
   aura::Window* GetWindowAtScreenPoint(const gfx::Point& point) override;
 
   // ui:OSExchangeDataProviderFactory::Factory:
   std::unique_ptr<OSExchangeData::Provider> BuildProvider() override;
 
   static MusClient* instance_;
 
   service_manager::Connector* connector_;
   service_manager::Identity identity_;
 
+  base::ObserverList<MusClientObserver> observer_list_;
+
   std::unique_ptr<wm::WMState> wm_state_;
 
   std::unique_ptr<ScreenMus> screen_;
 
   std::unique_ptr<aura::PropertyConverter> property_converter_;
 
   std::unique_ptr<aura::WindowTreeClient> window_tree_client_;
 
   std::unique_ptr<aura::GpuService> gpu_service_;
 
   std::unique_ptr<aura::MusContextFactory> compositor_context_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MusClient);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_MUS_MUS_CLIENT_H_