[Extension ServiceWorkers] Allow service worker registration

extensions/browser/extension_protocols.cc

 // 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.
 
 #include "extensions/browser/extension_protocols.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 177 matching lines @@
         weak_factory_(this) {
     if (follow_symlinks_anywhere) {
       resource_.set_follow_symlinks_anywhere();
     }
   }
 
   void GetResponseInfo(net::HttpResponseInfo* info) override {
     *info = response_info_;
   }
 
+  // This always returns 200 because a URLRequestExtensionJob will only get
+  // created in MaybeCreateJob() if the file exists.
+  int GetResponseCode() const override { return 200; }
+
   void Start() override {
     request_timer_.reset(new base::ElapsedTimer());
     base::FilePath* read_file_path = new base::FilePath;
     base::Time* last_modified_time = new base::Time();
     bool posted = BrowserThread::PostBlockingPoolTaskAndReply(
         FROM_HERE,
         base::Bind(&ReadResourceFilePathAndLastModifiedTime,
                    resource_,
                    directory_path_,
                    base::Unretained(read_file_path),
@@ skipping 345 matching lines @@
   return new net::HttpResponseHeaders(raw_headers);
 }
 
 net::URLRequestJobFactory::ProtocolHandler* CreateExtensionProtocolHandler(
     bool is_incognito,
     extensions::InfoMap* extension_info_map) {
   return new ExtensionProtocolHandler(is_incognito, extension_info_map);
 }
 
 }  // namespace extensions