Remove Clone() from CannedBrowsingData*Helper classes

chrome/browser/browsing_data/browsing_data_channel_id_helper.h

 // Copyright 2014 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_BROWSING_DATA_BROWSING_DATA_CHANNEL_ID_HELPER_H_
 #define CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_CHANNEL_ID_HELPER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 35 matching lines @@
 };
 
 // This class is a thin wrapper around BrowsingDataChannelIDHelper that
 // does not fetch its information from the ChannelIDService, but gets them
 // passed as a parameter during construction.
 class CannedBrowsingDataChannelIDHelper
     : public BrowsingDataChannelIDHelper {
  public:
   CannedBrowsingDataChannelIDHelper();
 
-  // Return a copy of the ChannelID helper. Only one consumer can use the
-  // StartFetching method at a time, so we need to create a copy of the helper
-  // every time we instantiate a cookies tree model for it.
-  CannedBrowsingDataChannelIDHelper* Clone();
-
   // Add an ChannelID to the set of canned channel IDs that is
   // returned by this helper.
   void AddChannelID(
       const net::ChannelIDStore::ChannelID& channel_id);
 
   // Clears the list of canned channel IDs.
   void Reset();
 
   // True if no ChannelIDs are currently stored.
   bool empty() const;
@@ skipping 13 matching lines @@
   typedef std::map<std::string, net::ChannelIDStore::ChannelID>
       ChannelIDMap;
   ChannelIDMap channel_id_map_;
 
   FetchResultCallback completion_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(CannedBrowsingDataChannelIDHelper);
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_CHANNEL_ID_HELPER_H_