ServiceWorker: Bypass SW when the script doesn't have fetch handler

content/browser/service_worker/foreign_fetch_request_handler.cc

 // 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.
 
 #include "content/browser/service_worker/foreign_fetch_request_handler.h"
 
 #include <string>
 
 #include "base/macros.h"
 #include "content/browser/service_worker/service_worker_context_wrapper.h"
@@ skipping 179 matching lines @@
     }
   }
 
   const url::Origin& request_origin = job->request()->initiator();
   bool origin_matches = active_version->foreign_fetch_origins().empty();
   for (const url::Origin& origin : active_version->foreign_fetch_origins()) {
     if (request_origin.IsSameOriginWith(origin))
       origin_matches = true;
   }
 
-  if (!scope_matches || !origin_matches) {
+  if (!scope_matches || !origin_matches ||
+      !active_version->has_fetch_handler()) {

[Marijn Kruisselbrink, 2016/05/27 16:18:12]

This is probably not correct. Foreign fetch events get delivered to the
"foreignfetch" event, not the "fetch" event.

[shimazu, 2016/05/30 05:41:59]

Sorry, it's true!
Done.

     job->FallbackToNetwork();
     return;
   }
 
   target_worker_ = active_version;
   job->ForwardToServiceWorker();
 }
 
 void ForeignFetchRequestHandler::OnPrepareToRestart() {
   use_network_ = true;
@@ skipping 10 matching lines @@
   }
   return target_worker_.get();
 }
 
 void ForeignFetchRequestHandler::ClearJob() {
   job_.reset();
   target_worker_ = nullptr;
 }
 
 }  // namespace content