Validate hash_sha256 checksum on .crx update.

extensions/browser/updater/extension_downloader_delegate.h

 // Copyright (c) 2012 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 EXTENSIONS_BROWSER_UPDATER_EXTENSION_DOWNLOADER_DELEGATE_H_
 #define EXTENSIONS_BROWSER_UPDATER_EXTENSION_DOWNLOADER_DELEGATE_H_
 
 #include <set>
 #include <string>
 
@@ skipping 66 matching lines @@
                                          Error error,
                                          const PingResult& ping_result,
                                          const std::set<int>& request_ids);
 
   // Invoked if the extension had an update available and its crx was
   // successfully downloaded to |path|. |ownership_passed| is true if delegate
   // should get ownership of the file.
   virtual void OnExtensionDownloadFinished(
       const std::string& id,
       const base::FilePath& path,
+      const std::string& hash,
       bool file_ownership_passed,
       const GURL& download_url,
       const std::string& version,
       const PingResult& ping_result,
       const std::set<int>& request_ids) = 0;
 
   // The remaining methods are used by the ExtensionDownloader to retrieve
   // information about extensions from the delegate.
 
   // Invoked to fill the PingData for the given extension id. Returns false
@@ skipping 18 matching lines @@
   // Determines if a given extension should be forced to update and (if so)
   // what the source of this forcing is (i.e. what string will be passed
   // in |installsource| as part of the update query parameters). The default
   // implementation always returns |false|.
   virtual bool ShouldForceUpdate(const std::string& id, std::string* source);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_UPDATER_EXTENSION_DOWNLOADER_DELEGATE_H_