[Mac] Desaturate the Favicon for Network Errors

chrome/browser/favicon/favicon_utils.h

 // Copyright (c) 2012 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 CHROME_BROWSER_FAVICON_FAVICON_UTILS_H_
 #define CHROME_BROWSER_FAVICON_FAVICON_UTILS_H_
 
 #include "components/favicon/content/content_favicon_driver.h"
 
+namespace content {
+class WebContents;
+}  // namespace content
+
+namespace gfx {
+class Image;
+}  // namespace gfx
+
 namespace favicon {
 
 // Creates a ContentFaviconDriver and associates it with |web_contents| if none
 // exists yet.
 //
 // This is a helper method for ContentFaviconDriver::CreateForWebContents() that
 // gets KeyedService factories from the Profile linked to web_contents.
 void CreateContentFaviconDriverForWebContents(
     content::WebContents* web_contents);
 
 // Returns whether the favicon should be displayed. If this returns false, no
 // space is provided for the favicon, and the favicon is never displayed.
 bool ShouldDisplayFavicon(content::WebContents* web_contents);
 
+// Retrieves the favicon from given WebContents. If contents contain a
+// network error, desaturate the favicon.
+gfx::Image TabFaviconFromWebContents(content::WebContents* contents);
+
 }  // namespace favicon
 
 #endif  // CHROME_BROWSER_FAVICON_FAVICON_UTILS_H_