Suppress JavaScript dialogs when a tab puts itself into fullscreen.

apps/custom_launcher_page_contents.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_CUSTOM_LAUNCHER_PAGE_CONTENTS_H_
 #define APPS_CUSTOM_LAUNCHER_PAGE_CONTENTS_H_
 
 #include <memory>
 
 #include "content/public/browser/web_contents_delegate.h"
@@ skipping 31 matching lines @@
   content::WebContents* OpenURLFromTab(
       content::WebContents* source,
       const content::OpenURLParams& params) override;
   void AddNewContents(content::WebContents* source,
                       content::WebContents* new_contents,
                       WindowOpenDisposition disposition,
                       const gfx::Rect& initial_rect,
                       bool user_gesture,
                       bool* was_blocked) override;
   bool IsPopupOrPanel(const content::WebContents* source) const override;
-  bool ShouldSuppressDialogs(content::WebContents* source) override;
+  bool ShouldSuppressDialogs(content::WebContents* source,
+                             bool before_unload) override;
   bool PreHandleGestureEvent(content::WebContents* source,
                              const blink::WebGestureEvent& event) override;
   content::ColorChooser* OpenColorChooser(
       content::WebContents* web_contents,
       SkColor color,
       const std::vector<content::ColorSuggestion>& suggestions) override;
   void RunFileChooser(content::RenderFrameHost* render_frame_host,
                       const content::FileChooserParams& params) override;
   void RequestToLockMouse(content::WebContents* web_contents,
                           bool user_gesture,
@@ skipping 12 matching lines @@
   std::unique_ptr<extensions::AppWebContentsHelper> helper_;
 
   std::string extension_id_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomLauncherPageContents);
 };
 
 }  // namespace apps
 
 #endif  // APPS_CUSTOM_LAUNCHER_PAGE_CONTENTS_H_