Delete the omahaproxy-backed extension blacklist and clear its entries from the

chrome/browser/chromeos/extensions/external_cache.h

 // Copyright (c) 2013 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_CHROMEOS_EXTENSIONS_EXTERNAL_CACHE_H_
 #define CHROME_BROWSER_CHROMEOS_EXTENSIONS_EXTERNAL_CACHE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 74 matching lines @@
       const std::set<int>& request_ids) OVERRIDE;
 
   virtual void OnExtensionDownloadFinished(
       const std::string& id,
       const base::FilePath& path,
       const GURL& download_url,
       const std::string& version,
       const PingResult& ping_result,
       const std::set<int>& request_ids) OVERRIDE;
 
-  virtual void OnBlacklistDownloadFinished(
-      const std::string& data,
-      const std::string& package_hash,
-      const std::string& version,
-      const PingResult& ping_result,
-      const std::set<int>& request_ids) OVERRIDE;
-
   virtual bool IsExtensionPending(const std::string& id) OVERRIDE;
 
   virtual bool GetExtensionExistingVersion(const std::string& id,
                                            std::string* version) OVERRIDE;
 
   // Starts a cache update check immediately.
   void CheckCacheNow();
 
   // Notifies the that the cache has been updated, providing
   // extensions loader with an updated list of extensions.
@@ skipping 69 matching lines @@
   // Unique sequence token so that tasks posted by the ExternalCache are
   // executed sequentially in the blocking pool.
   base::SequencedWorkerPool::SequenceToken worker_pool_token_;
 
   DISALLOW_COPY_AND_ASSIGN(ExternalCache);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_EXTERNAL_CACHE_H_