Provide assumed favicon for intents if service provider page was never visited.

chrome/browser/favicon/favicon_service.h

 // Copyright (c) 2011 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_
 #pragma once
 
 #include <vector>
 
@@ skipping 64 matching lines @@
   // 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);
 
   // Marks all types of favicon for the page as being out of date.
   void SetFaviconOutOfDateForPage(const GURL& page_url);
 
+  // Clone a favicon from an existing page. This associates the favicon from

[sky, 2011/11/16 17:26:00]

Clarify this clones all icons, not just the favicon.

[groby-ooo-7-16, 2011/11/17 00:37:55]

Done.

+  // |old_page_url| with |new_page_url|, provided |new_page_url| has no
+  // recorded association.
+  // 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);

[sky, 2011/11/16 17:26:00]

This is worrisome. There's nothing stopping someone from doing something like
CloneFavicon('evil.com', 'good.com'), which we wouldn't want. Could we restrict
this to the same domain? so that you only get to change the path?

[groby-ooo-7-16, 2011/11/17 00:37:55]

I'm confused - how is that any more of a security risk than e.g. allowing a call
to SetFavicon? This is chrome-internal code - if an attacker can call that
directly, security is compromised anyways?

(Added anyways, just in case ;)

[sky, 2011/11/17 04:49:01]

I wasn't worried about the attack risk (as you say, this is chrome code), but
more so of someone accidentally using the API for a case we don't need to
support nor want to support.

+
   // Allows the importer to set many favicons for many pages at once. The pages
   // must exist, any favicon sets for unknown pages will be discarded. Existing
   // favicons will not be overwritten.
   void SetImportedFavicons(
       const std::vector<history::ImportedFaviconUsage>& favicon_usage);
 
   // Sets the favicon for a page.
   void SetFavicon(const GURL& page_url,
                   const GURL& icon_url,
                   const std::vector<unsigned char>& image_data,
                   history::IconType icon_type);
 
  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_