Extract Favicon Download logic from FaviconTabHelper

chrome/browser/favicon/favicon_tab_helper.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_TAB_HELPER_H_
 #define CHROME_BROWSER_FAVICON_FAVICON_TAB_HELPER_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/callback.h"
+#include "chrome/browser/favicon/favicon_download_helper_delegate.h"
 #include "chrome/browser/favicon/favicon_handler_delegate.h"
 #include "chrome/browser/history/history_types.h"
 #include "chrome/common/favicon_url.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/browser/web_contents_user_data.h"
 
 namespace gfx {
 class Image;
 }
 
 class GURL;
+class FaviconDownloadHelper;
 class FaviconHandler;
 class Profile;
 class SkBitmap;
 
 // FaviconTabHelper works with FaviconHandlers to fetch the favicons.
 //
 // FetchFavicon fetches the given page's icons. It requests the icons from the
 // history backend. If the icon is not available or expired, the icon will be
 // downloaded and saved in the history backend.
 //
 // DownloadImage downloads the specified icon and returns it through the given
 // callback.
 //
 class FaviconTabHelper : public content::WebContentsObserver,
                          public FaviconHandlerDelegate,
+                         public FaviconDownloadHelperDelegate,
                          public content::WebContentsUserData<FaviconTabHelper> {
  public:
   virtual ~FaviconTabHelper();
 
   // Initiates loading the favicon for the specified url.
   void FetchFavicon(const GURL& url);
 
   // Returns the favicon for this tab, or IDR_DEFAULT_FAVICON if the tab does
   // not have a favicon. The default implementation uses the current navigation
   // entry. This will return an empty bitmap if there are no navigation
   // entries, which should rarely happen.
   gfx::Image GetFavicon() const;
 
   // Returns true if we have the favicon for the page.
   bool FaviconIsValid() const;
 
   // Returns whether the favicon should be displayed. If this returns false, no
   // space is provided for the favicon, and the favicon is never displayed.
   virtual bool ShouldDisplayFavicon();
 
+  // Message Handler.  Must be public, because also called from
+  // PrerenderContents.
+  virtual void OnUpdateFaviconURL(int32 page_id,
+      const std::vector<FaviconURL>& candidates) OVERRIDE;
+
   // Saves the favicon for the current page.
   void SaveFavicon();
 
   // Initiates loading an image from given |image_url|. Returns a download id
   // for caller to track the request. When download completes, |callback| is
   // called with the three params: the download_id, a boolean flag to indicate
   // whether the download succeeds and a SkBitmap as the downloaded image.
   // Note that |image_size| is a hint for images with multiple sizes. The
   // downloaded image is not resized to the given image_size. If 0 is passed,
   // the first frame of the image is returned.
   typedef base::Callback<void(int, bool, const SkBitmap&)>
       ImageDownloadCallback;
   int DownloadImage(const GURL& image_url,
                     int image_size,
                     history::IconType icon_type,
                     const ImageDownloadCallback& callback);
 
-  // Message Handler.  Must be public, because also called from
-  // PrerenderContents.
-  void OnUpdateFaviconURL(int32 page_id,
-                          const std::vector<FaviconURL>& candidates);
-
   // FaviconHandlerDelegate methods.
   virtual content::NavigationEntry* GetActiveEntry() OVERRIDE;
   virtual int StartDownload(const GURL& url, int image_size) OVERRIDE;
   virtual void NotifyFaviconUpdated() OVERRIDE;
 
  private:
   explicit FaviconTabHelper(content::WebContents* web_contents);
   friend class content::WebContentsUserData<FaviconTabHelper>;
 
   // content::WebContentsObserver overrides.
   virtual void NavigateToPendingEntry(
       const GURL& url,
       content::NavigationController::ReloadType reload_type) OVERRIDE;
   virtual void DidNavigateMainFrame(
       const content::LoadCommittedDetails& details,
       const content::FrameNavigateParams& params) OVERRIDE;
-  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
 
-  // Message handler for IconHostMsg_DidDownloadFavicon.
-  void OnDidDownloadFavicon(int id,
-                            const GURL& image_url,
-                            bool errored,
-                            int requested_size,
-                            const std::vector<SkBitmap>& bitmaps);
+  // FaviconDownloadHelperDelegate overrides.
+  virtual void OnDidDownloadFavicon(
+      int id,
+      const GURL& image_url,
+      bool errored,
+      int requested_size,
+      const std::vector<SkBitmap>& bitmaps) OVERRIDE;
 
   Profile* profile_;
 
+  scoped_ptr<FaviconDownloadHelper> favicon_download_helper_;
+
   scoped_ptr<FaviconHandler> favicon_handler_;
 
   // Handles downloading touchicons. It is NULL if
   // browser_defaults::kEnableTouchIcon is false.
   scoped_ptr<FaviconHandler> touch_icon_handler_;
 
   DISALLOW_COPY_AND_ASSIGN(FaviconTabHelper);
 };
 
 #endif  // CHROME_BROWSER_FAVICON_FAVICON_TAB_HELPER_H_