Service Worker: FetchEvent.preventDefault() results in a network error

Source/modules/serviceworkers/RespondWithObserver.cpp

 // 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 "config.h"
 #include "modules/serviceworkers/RespondWithObserver.h"
 
 #include "bindings/core/v8/ScriptFunction.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptValue.h"
@@ skipping 56 matching lines @@
 {
     return new RespondWithObserver(context, eventID, requestMode, frameType);
 }
 
 void RespondWithObserver::contextDestroyed()
 {
     ContextLifecycleObserver::contextDestroyed();
     m_state = Done;
 }
 
-void RespondWithObserver::didDispatchEvent()
+void RespondWithObserver::didDispatchEvent(bool defaultPrevented)
 {
     ASSERT(executionContext());
     if (m_state != Initial)
         return;
+
+    if (defaultPrevented) {
+        responseWasRejected();
+        return;
+    }
+
     ServiceWorkerGlobalScopeClient::from(executionContext())->didHandleFetchEvent(m_eventID);
     m_state = Done;
 }
 
 void RespondWithObserver::respondWith(ScriptState* scriptState, const ScriptValue& value, ExceptionState& exceptionState)
 {
     ASSERT(RuntimeEnabledFeatures::serviceWorkerOnFetchEnabled());
     if (m_state != Initial) {
         exceptionState.throwDOMException(InvalidStateError, "The fetch event has already been responded to.");
         return;
@@ skipping 44 matching lines @@
 RespondWithObserver::RespondWithObserver(ExecutionContext* context, int eventID, WebURLRequest::FetchRequestMode requestMode, WebURLRequest::FrameType frameType)
     : ContextLifecycleObserver(context)
     , m_eventID(eventID)
     , m_requestMode(requestMode)
     , m_frameType(frameType)
     , m_state(Initial)
 {
 }
 
 } // namespace blink