[Chromecast] Add support for z-order and window focus.

chromecast/graphics/cast_window_manager_aura.h

 // Copyright 2017 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 CHROMECAST_GRAPHICS_CAST_WINDOW_MANAGER_AURA_H_
 #define CHROMECAST_GRAPHICS_CAST_WINDOW_MANAGER_AURA_H_
 
 #include <memory>
 
 #include "base/macros.h"
-#include "base/observer_list.h"
 #include "chromecast/graphics/cast_vsync_settings.h"
 #include "chromecast/graphics/cast_window_manager.h"
 
 namespace aura {
-class Window;
 namespace client {
 class DefaultCaptureClient;
 }  // namespace client
 }  // namespace aura
 
 namespace chromecast {
 
+class CastFocusClientAura;
 class CastWindowTreeHost;
 
 class CastWindowManagerAura : public CastWindowManager,
                               private CastVSyncSettings::Observer {
  public:
   ~CastWindowManagerAura() override;
 
   // CastWindowManager implementation:
   void TearDown() override;
   void AddWindow(gfx::NativeView window) override;
 
  private:
   friend class CastWindowManager;
 
   // This class should only be instantiated by CastWindowManager::Create.
   explicit CastWindowManagerAura(bool enable_input);
 
   // CastVSyncSettings::Observer implementation:
   void OnVSyncIntervalChanged(base::TimeDelta interval) override;
 
   void Setup();
 
   const bool enable_input_;
   std::unique_ptr<CastWindowTreeHost> window_tree_host_;
   std::unique_ptr<aura::client::DefaultCaptureClient> capture_client_;
+  std::unique_ptr<CastFocusClientAura> focus_client_;
 
   DISALLOW_COPY_AND_ASSIGN(CastWindowManagerAura);
 };
 
 }  // namespace chromecast
 
 #endif  // CHROMECAST_GRAPHICS_CAST_WINDOW_MANAGER_AURA_H_