[LargeIconService] Make check_seen param optional for fetching

components/favicon/core/large_icon_service.h

 // Copyright 2015 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 COMPONENTS_FAVICON_CORE_LARGE_ICON_SERVICE_H_
 #define COMPONENTS_FAVICON_CORE_LARGE_ICON_SERVICE_H_
 
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 57 matching lines @@
   // Fetches the best large icon for the page at |page_url| from a Google
   // favicon server and stores the result in the FaviconService database
   // (implemented in HistoryService). The write will be a no-op if the local
   // favicon database contains an icon for |page_url|, so clients are
   // encouraged to use GetLargeIconOrFallbackStyle() first.
   //
   // A minimum size |min_source_size_in_pixel| can be specified as a constraint.
   // |desired_size_in_pixel| serves only as a hint to the service, no guarantees
   // on the fetched size are provided.
   //
+  // Unless you are sure |page_url| is a public URL (known to Google Search),
+  // set |may_page_url_be_private| to true. This slighty increases the chance of
+  // a failure (e.g. if the URL _is_ private) but it makes sure Google servers
+  // do not crawl a private URL as a result of this call.
+  //
   // The callback is triggered when the operation finishes, where |success|
   // tells whether the fetch actually managed to database a new icon in the
   // FaviconService.
   //
   // WARNING: This function will share the |page_url| with a Google server. This
   // Can be used only for urls that are not privacy sensitive or for users that
   // sync their history with Google servers.
   // TODO(jkrcal): It is not clear from the name of this function, that it
   // actually adds the icon to the local cache. Maybe "StoreLargeIcon..."?
   void GetLargeIconOrFallbackStyleFromGoogleServerSkippingLocalCache(
       const GURL& page_url,
       int min_source_size_in_pixel,
       int desired_size_in_pixel,
+      bool may_page_url_be_private,
       const base::Callback<void(bool success)>& callback);
 
  private:
   base::CancelableTaskTracker::TaskId GetLargeIconOrFallbackStyleImpl(
       const GURL& page_url,
       int min_source_size_in_pixel,
       int desired_size_in_pixel,
       const favicon_base::LargeIconCallback& raw_bitmap_callback,
       const favicon_base::LargeIconImageCallback& image_callback,
       base::CancelableTaskTracker* tracker);
 
   FaviconService* favicon_service_;
   scoped_refptr<base::TaskRunner> background_task_runner_;
 
   // A pre-populated list of icon types to consider when looking for large
   // icons. This is an optimization over populating an icon type vector on each
   // request.
   std::vector<int> large_icon_types_;
 
   std::unique_ptr<image_fetcher::ImageFetcher> image_fetcher_;
 
   DISALLOW_COPY_AND_ASSIGN(LargeIconService);
 };
 
 }  // namespace favicon
 
 #endif  // COMPONENTS_FAVICON_CORE_LARGE_ICON_SERVICE_H_