Remove Clone() from CannedBrowsingData*Helper classes

chrome/browser/browsing_data/browsing_data_service_worker_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_SERVICE_WORKER_HELPER_H_
 #define CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_SERVICE_WORKER_HELPER_H_
 
 #include <list>
 #include <set>
 #include <string>
@@ skipping 89 matching lines @@
 
     bool operator<(const PendingServiceWorkerUsageInfo& other) const;
 
     GURL origin;
     std::vector<GURL> scopes;
   };
 
   explicit CannedBrowsingDataServiceWorkerHelper(
       content::ServiceWorkerContext* context);
 
-  // Return a copy of the ServiceWorker 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.
-  CannedBrowsingDataServiceWorkerHelper* Clone();
-
   // Add a Service Worker to the set of canned Service Workers that is
   // returned by this helper.
   void AddServiceWorker(const GURL& origin, const std::vector<GURL>& scopes);
 
   // Clear the list of canned Service Workers.
   void Reset();
 
   // True if no Service Workers are currently stored.
   bool empty() const;
 
@@ skipping 12 matching lines @@
 
  private:
   virtual ~CannedBrowsingDataServiceWorkerHelper();
 
   std::set<PendingServiceWorkerUsageInfo> pending_service_worker_info_;
 
   DISALLOW_COPY_AND_ASSIGN(CannedBrowsingDataServiceWorkerHelper);
 };
 
 #endif  // CHROME_BROWSER_BROWSING_DATA_BROWSING_DATA_SERVICE_WORKER_HELPER_H_