Fix races when the same bits are downloaded from 2 URLs.

shell/application_manager/network_fetcher.h

 // Copyright 2015 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 SHELL_APPLICATION_MANAGER_NETWORK_FETCHER_H_
 #define SHELL_APPLICATION_MANAGER_NETWORK_FETCHER_H_
 
 #include "shell/application_manager/fetcher.h"
 
 #include "base/files/file_path.h"
@@ skipping 28 matching lines @@
                                uint32_t skip) override;
 
   static void RecordCacheToURLMapping(const base::FilePath& path,
                                       const GURL& url);
 
   // AppIds should be be both predictable and unique, but any hash would work.
   // Currently we use sha256 from crypto/secure_hash.h
   static bool ComputeAppId(const base::FilePath& path,
                            std::string* digest_string);
 
-  static bool RenameToAppId(const base::FilePath& old_path,
+  static bool RenameToAppId(const GURL& url,
+                            const base::FilePath& old_path,
                             base::FilePath* new_path);
 
   void CopyCompleted(base::Callback<void(const base::FilePath&, bool)> callback,
                      bool success);
 
   void AsPath(
       base::TaskRunner* task_runner,
       base::Callback<void(const base::FilePath&, bool)> callback) override;
 
   std::string MimeType() override;
@@ skipping 13 matching lines @@
   base::FilePath path_;
   base::WeakPtrFactory<NetworkFetcher> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkFetcher);
 };
 
 }  // namespace shell
 }  // namespace mojo
 
 #endif  // SHELL_APPLICATION_MANAGER_NETWORK_FETCHER_H_