Add app.window.alphaEnabled() and onAlphaEnabledChanged.

apps/ui/views/native_app_window_views.h

 // Copyright 2014 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 APPS_UI_VIEWS_NATIVE_APP_WINDOW_VIEWS_H_
 #define APPS_UI_VIEWS_NATIVE_APP_WINDOW_VIEWS_H_
 
 #include "apps/size_constraints.h"
 #include "apps/ui/native_app_window.h"
 #include "base/observer_list.h"
@@ skipping 34 matching lines @@
 class NativeAppWindowViews : public NativeAppWindow,
                              public content::WebContentsObserver,
                              public views::WidgetDelegateView,
                              public views::WidgetObserver {
  public:
   NativeAppWindowViews();
   virtual ~NativeAppWindowViews();
   void Init(AppWindow* app_window,
             const AppWindow::CreateParams& create_params);
 
+  // Signal that CanHaveTransparentBackground has changed.
+  void CanHaveAlphaEnabledChanged();

[tapted, 2014/07/14 03:30:24]

maybe prefix with 'On'? reads a bit like it should return a value

[jackhou1, 2014/07/14 04:51:03]

Done.

+
   views::Widget* widget() { return widget_; }
 
   void set_window_for_testing(views::Widget* window) { widget_ = window; }
   void set_web_view_for_testing(views::WebView* view) { web_view_ = view; }
 
  protected:
   AppWindow* app_window() { return app_window_; }
   const AppWindow* app_window() const { return app_window_; }
 
   const views::Widget* widget() const { return widget_; }
@@ skipping 84 matching lines @@
   virtual SkColor ActiveFrameColor() const OVERRIDE;
   virtual SkColor InactiveFrameColor() const OVERRIDE;
   virtual gfx::Insets GetFrameInsets() const OVERRIDE;
   virtual void HideWithApp() OVERRIDE;
   virtual void ShowWithApp() OVERRIDE;
   virtual void UpdateShelfMenu() OVERRIDE;
   virtual gfx::Size GetContentMinimumSize() const OVERRIDE;
   virtual gfx::Size GetContentMaximumSize() const OVERRIDE;
   virtual void SetContentSizeConstraints(const gfx::Size& min_size,
                                          const gfx::Size& max_size) OVERRIDE;
+  virtual bool CanHaveAlphaEnabled() const OVERRIDE;
 
   // web_modal::WebContentsModalDialogHost implementation.
   virtual gfx::NativeView GetHostView() const OVERRIDE;
   virtual gfx::Point GetDialogPosition(const gfx::Size& size) OVERRIDE;
   virtual gfx::Size GetMaximumDialogSize() OVERRIDE;
   virtual void AddObserver(
       web_modal::ModalDialogHostObserver* observer) OVERRIDE;
   virtual void RemoveObserver(
       web_modal::ModalDialogHostObserver* observer) OVERRIDE;
 
  private:
   // Informs modal dialogs that they need to update their positions.
   void OnViewWasResized();
 
   AppWindow* app_window_;  // Not owned.
   views::WebView* web_view_;
   views::Widget* widget_;
 
   scoped_ptr<SkRegion> draggable_region_;
 
   bool frameless_;
-  bool transparent_background_;
   bool resizable_;
   apps::SizeConstraints size_constraints_;
 
   views::UnhandledKeyboardEventHandler unhandled_keyboard_event_handler_;
 
   ObserverList<web_modal::ModalDialogHostObserver> observer_list_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeAppWindowViews);
 };
 
 }  // namespace apps
 
 #endif  // APPS_UI_VIEWS_NATIVE_APP_WINDOW_VIEWS_H_