Add notification settings button to ARC notifications.

ui/arc/notification/arc_custom_notification_view.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_ARC_NOTIFICATION_ARC_CUSTOM_NOTIFICATION_VIEW_H_
 #define UI_ARC_NOTIFICATION_ARC_CUSTOM_NOTIFICATION_VIEW_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 25 matching lines @@
       public ArcNotificationSurfaceManager::Observer {
  public:
   explicit ArcCustomNotificationView(ArcCustomNotificationItem* item);
   ~ArcCustomNotificationView() override;
 
   std::unique_ptr<message_center::CustomNotificationContentViewDelegate>
   CreateContentViewDelegate();
 
  private:
   class ContentViewDelegate;
-  class CloseButton;
+  class ControlButton;
   class EventForwarder;
+  class SettingsButton;
   class SlideHelper;
 
-  void CreateFloatingCloseButton();
+  void CreateFloatingControlButtons();
   void SetSurface(exo::NotificationSurface* surface);
   void UpdatePreferredSize();
-  void UpdateCloseButtonVisiblity();
+  void UpdateControlButtonsVisiblity();
   void UpdatePinnedState();
   void UpdateSnapshot();
   void AttachSurface();
 
   // views::NativeViewHost
   void ViewHierarchyChanged(
       const ViewHierarchyChangedDetails& details) override;
   void Layout() override;
   void OnPaint(gfx::Canvas* canvas) override;
   void OnKeyEvent(ui::KeyEvent* event) override;
@@ skipping 30 matching lines @@
   // Using a pre-target event handler instead of a target handler on the surface
   // window because it has descendant aura::Window and the events on them need
   // to be handled as well.
   // TODO(xiyuan): Revisit after exo::Surface no longer has an aura::Window.
   std::unique_ptr<EventForwarder> event_forwarder_;
 
   // A helper to observe slide transform/animation and use surface layer copy
   // when a slide is in progress and restore the surface when it finishes.
   std::unique_ptr<SlideHelper> slide_helper_;
 
-  // A close button on top of NotificationSurface. Needed because the
+  // A control buttons on top of NotificationSurface. Needed because the
   // aura::Window of NotificationSurface is added after hosting widget's
-  // RootView thus standard notification close button is always below
+  // RootView thus standard notification control buttons are always below
   // it.
-  std::unique_ptr<views::Widget> floating_close_button_widget_;
+  std::unique_ptr<views::Widget> floating_control_buttons_widget_;
 
-  views::ImageButton* floating_close_button_ = nullptr;
+  views::View* control_buttons_view_ = nullptr;
+  views::ImageButton* close_button_ = nullptr;
+  views::ImageButton* settings_button_ = nullptr;
 
   // Protects from call loops between Layout and OnWindowBoundsChanged.
   bool in_layout_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(ArcCustomNotificationView);
 };
 
 }  // namespace arc
 
 #endif  // UI_ARC_NOTIFICATION_ARC_CUSTOM_NOTIFICATION_VIEW_H_