Make it possible to set the display mode from Chromium

extensions/browser/app_window/app_window.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 EXTENSIONS_BROWSER_APP_WINDOW_APP_WINDOW_H_
 #define EXTENSIONS_BROWSER_APP_WINDOW_APP_WINDOW_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 363 matching lines @@
   bool IsPopupOrPanel(const content::WebContents* source) const override;
   void MoveContents(content::WebContents* source,
                     const gfx::Rect& pos) override;
   void NavigationStateChanged(content::WebContents* source,
                               content::InvalidateTypes changed_flags) override;
   void EnterFullscreenModeForTab(content::WebContents* source,
                                  const GURL& origin) override;
   void ExitFullscreenModeForTab(content::WebContents* source) override;
   bool IsFullscreenForTabOrPending(
       const content::WebContents* source) const override;
+  blink::WebDisplayMode GetDisplayMode(
+      const content::WebContents* source) const override;
   void RequestMediaAccessPermission(
       content::WebContents* web_contents,
       const content::MediaStreamRequest& request,
       const content::MediaResponseCallback& callback) override;
   bool CheckMediaAccessPermission(content::WebContents* web_contents,
                                   const GURL& security_origin,
                                   content::MediaStreamType type) override;
   content::WebContents* OpenURLFromTab(
       content::WebContents* source,
       const content::OpenURLParams& params) override;
@@ skipping 162 matching lines @@
   bool requested_alpha_enabled_;
 
   base::WeakPtrFactory<AppWindow> image_loader_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AppWindow);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_APP_WINDOW_APP_WINDOW_H_