Merge to M58: Resolve preloadResponse of Navigation Preload even if the response body is empty.

third_party/WebKit/Source/modules/serviceworkers/FetchEvent.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 "modules/serviceworkers/FetchEvent.h"
 
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/ToV8.h"
 #include "bindings/core/v8/V8HiddenValue.h"
 #include "modules/fetch/BytesConsumerForDataConsumerHandle.h"
@@ skipping 95 matching lines @@
 }
 
 void FetchEvent::onNavigationPreloadResponse(
     ScriptState* scriptState,
     std::unique_ptr<WebURLResponse> response,
     std::unique_ptr<WebDataConsumerHandle> dataConsumeHandle) {
   if (!scriptState->contextIsValid())
     return;
   DCHECK(m_preloadResponseProperty);
   ScriptState::Scope scope(scriptState);
-  FetchResponseData* responseData = FetchResponseData::createWithBuffer(
-      new BodyStreamBuffer(scriptState, new BytesConsumerForDataConsumerHandle(
-                                            scriptState->getExecutionContext(),
-                                            std::move(dataConsumeHandle))));
+  FetchResponseData* responseData =
+      dataConsumeHandle
+          ? FetchResponseData::createWithBuffer(new BodyStreamBuffer(
+                scriptState, new BytesConsumerForDataConsumerHandle(
+                                 scriptState->getExecutionContext(),
+                                 std::move(dataConsumeHandle))))
+          : FetchResponseData::create();
   Vector<KURL> urlList(1);
   urlList[0] = response->url();
   responseData->setURLList(urlList);
   responseData->setStatus(response->httpStatusCode());
   responseData->setStatusMessage(response->httpStatusText());
   responseData->setResponseTime(response->toResourceResponse().responseTime());
   const HTTPHeaderMap& headers(
       response->toResourceResponse().httpHeaderFields());
   for (const auto& header : headers) {
     responseData->headerList()->append(header.key, header.value);
@@ skipping 15 matching lines @@
 }
 
 DEFINE_TRACE(FetchEvent) {
   visitor->trace(m_observer);
   visitor->trace(m_request);
   visitor->trace(m_preloadResponseProperty);
   ExtendableEvent::trace(visitor);
 }
 
 }  // namespace blink