Validate hash_sha256 checksum on .crx update.

chrome/browser/chromeos/extensions/external_cache.cc

 // 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.
 
 #include "chrome/browser/chromeos/extensions/external_cache.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/files/file_enumerator.h"
@@ skipping 163 matching lines @@
   } else {
     LOG(ERROR) << "ExternalCache failed to download extension " << id
                << ", error " << error;
     delegate_->OnExtensionDownloadFailed(id, error);
   }
 }
 
 void ExternalCache::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 extensions::ExtensionDownloaderDelegate::PingResult& ping_result,
     const std::set<int>& request_ids) {
   DCHECK(file_ownership_passed);
   local_cache_.PutExtension(id, path, version,
                             base::Bind(&ExternalCache::OnPutExtension,
                                        weak_ptr_factory_.GetWeakPtr(),
                                        id));
@@ skipping 151 matching lines @@
   OnPutExtension(id, file_path, file_ownership_passed);
   callback.Run(id, !file_ownership_passed);
 }
 
 std::string ExternalCache::Delegate::GetInstalledExtensionVersion(
     const std::string& id) {
   return std::string();
 }
 
 }  // namespace chromeos