service worker: Add CHECKs for investigating null http info bug.

content/browser/service_worker/service_worker_fetch_dispatcher.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 "content/browser/service_worker/service_worker_fetch_dispatcher.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 176 matching lines @@
   void Run(int request_id,
            ServiceWorkerFetchEventResult fetch_result,
            const ServiceWorkerResponse& response,
            base::Time dispatch_event_time) {
     const bool handled =
         (fetch_result == SERVICE_WORKER_FETCH_EVENT_RESULT_RESPONSE);
     if (!version_->FinishRequest(request_id, handled, dispatch_event_time))
       NOTREACHED() << "Should only receive one reply per event";
 
     // |fetch_dispatcher| is null if the URLRequest was killed.
-    if (fetch_dispatcher_)
+    if (fetch_dispatcher_) {
+      // TODO(falken): Remove this CHECK once https://crbug.com/485900 is
+      // resolved.
+      CHECK(version_->GetMainScriptHttpResponseInfo());
       fetch_dispatcher_->DidFinish(request_id, fetch_result, response);
+    }
   }
 
  private:
   base::WeakPtr<ServiceWorkerFetchDispatcher> fetch_dispatcher_;
   // Owns |this|.
   ServiceWorkerVersion* version_;
 
   DISALLOW_COPY_AND_ASSIGN(ResponseCallback);
 };
 
@@ skipping 78 matching lines @@
     ServiceWorkerStatusCode status) {
   EndNetLogEventWithServiceWorkerStatus(
       net_log_, net::NetLogEventType::SERVICE_WORKER_START_WORKER, status);
   DidFail(status);
 }
 
 void ServiceWorkerFetchDispatcher::DispatchFetchEvent() {
   DCHECK_EQ(EmbeddedWorkerStatus::RUNNING, version_->running_status())
       << "Worker stopped too soon after it was started.";
 
+  // TODO(falken): Remove this CHECK once https://crbug.com/485900 is resolved.
+  CHECK(version_->GetMainScriptHttpResponseInfo());
+
   DCHECK(!prepare_callback_.is_null());
   base::Closure prepare_callback = prepare_callback_;
   prepare_callback.Run();
 
   net_log_.BeginEvent(net::NetLogEventType::SERVICE_WORKER_FETCH_EVENT);
   int fetch_event_id;
   int event_finish_id;
   if (timeout_) {
     fetch_event_id = version_->StartRequestWithCustomTimeout(
         GetEventType(),
@@ skipping 159 matching lines @@
 }
 
 ServiceWorkerMetrics::EventType ServiceWorkerFetchDispatcher::GetEventType()
     const {
   if (request_->fetch_type == ServiceWorkerFetchType::FOREIGN_FETCH)
     return ServiceWorkerMetrics::EventType::FOREIGN_FETCH;
   return ResourceTypeToEventType(resource_type_);
 }
 
 }  // namespace content