Change FaviconData to be able to return data for multiple bitmaps for same icon URL

chrome/browser/favicon/favicon_service.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_SERVICE_H_
 #define CHROME_BROWSER_FAVICON_FAVICON_SERVICE_H_
 
 #include <vector>
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "chrome/browser/cancelable_request.h"
 #include "chrome/browser/history/history_types.h"
 #include "chrome/common/ref_counted_util.h"
 
 class GURL;
 class Profile;
 
 // The favicon service provides methods to access favicons. It calls the history
 // backend behind the scenes.
 //
 // This service is thread safe. Each request callback is invoked in the
 // thread that made the request.
 class FaviconService : public CancelableRequestProvider {
  public:
   explicit FaviconService(Profile* profile);
 
   virtual ~FaviconService();
 
-  // Callback for GetFavicon. If we have previously inquired about the favicon
-  // for this URL, |know_favicon| will be true, and the rest of the fields will
-  // be valid (otherwise they will be ignored).
-  //
-  // On |know_favicon| == true, |data| will either contain the PNG encoded
-  // favicon data, or it will be NULL to indicate that the site does not have
-  // a favicon (in other words, we know the site doesn't have a favicon, as
-  // opposed to not knowing anything). |expired| will be set to true if we
-  // refreshed the favicon "too long" ago and should be updated if the page
-  // is visited again.
+  // Callback for GetFavicon.
+  // If we have previously inquired about the favicon for this URL,
+  // |know_favicon| will be true, and the rest of the fields will be valid
+  // (otherwise they will be ignored).
+  // On |know_favicon| == true, |icon_url| will be set to the URL whose favicon
+  // sizes best match the optimal favicon sizes of 16x16 and 32x32.
+  // See history_types.h for a detailed description of the FaviconData struct.
+  // Third argument:
+  // a) If the callback is called as a result of GetFaviconForURL()
+  //   The third argument is a list of the icon URLs of the requested icon type
+  //   mapped to the passed in |page_url|.
+  // b) If the callback is called as a result of GetFavicon() or
+  //    UpdateFaviconMappingAndFetch()
+  //    The third argument has a single entry with the passed in |icon_url| if
+  //    it is known to the history backend. Otherwise, an empty vector is
+  // returned.
   typedef base::Callback<

[sky, 2012/08/23 15:50:38]

As discussed over IM, this is temporary. Long term we should have a separate
callback for the common case that doesn't pass in the vector. In fact the common
case is likely a gfx::Image and that's it.

       void(Handle,  // handle
-           history::FaviconData)>  // the type of favicon
+           history::FaviconData,
+           std::vector<GURL>)>
       FaviconDataCallback;
 
   typedef CancelableRequest<FaviconDataCallback> GetFaviconRequest;
 
   // Requests the |icon_type| of favicon. |consumer| is notified when the bits
   // have been fetched. |icon_url| is the URL of the icon itself, e.g.
   // <http://www.google.com/favicon.ico>.
   Handle GetFavicon(const GURL& icon_url,
                     history::IconType icon_type,
                     CancelableRequestConsumerBase* consumer,
@@ skipping 16 matching lines @@
   // priority of TOUCH_PRECOMPOSED_ICON, TOUCH_ICON and FAVICON.
   //
   // Note: this version is intended to be used to retrieve the favicon of a
   // page that has been browsed in the past. |expired| in the callback is
   // always false.
   Handle GetFaviconForURL(const GURL& page_url,
                           int icon_types,
                           CancelableRequestConsumerBase* consumer,
                           const FaviconDataCallback& callback);
 
-  // Requests the favicon for |favicon_id|. The |consumer| is notified when the
-  // bits have been fetched.
-  Handle GetFaviconForID(history::FaviconID favicon_id,
-                         CancelableRequestConsumerBase* consumer,
-                         const FaviconDataCallback& callback);
-
   // Marks all types of favicon for the page as being out of date.
   void SetFaviconOutOfDateForPage(const GURL& page_url);
 
   // Clones all icons from an existing page. This associates the icons from
   // |old_page_url| with |new_page_url|, provided |new_page_url| has no
   // recorded associations to any other icons.
   // Needed if you want to declare favicons (tentatively) in advance, before a
   // page is ever visited.
   void CloneFavicon(const GURL& old_page_url, const GURL& new_page_url);
 
@@ skipping 12 matching lines @@
  private:
   Profile* profile_;
 
   // Helper to forward an empty result if we cannot get the history service.
   void ForwardEmptyResultAsync(GetFaviconRequest* request);
 
   DISALLOW_COPY_AND_ASSIGN(FaviconService);
 };
 
 #endif  // CHROME_BROWSER_FAVICON_FAVICON_SERVICE_H_