Resolve preloadResponse of Navigation Preload even if the response body is empty.

third_party/WebKit/Source/modules/serviceworkers/FetchEvent.cpp

Index: third_party/WebKit/Source/modules/serviceworkers/FetchEvent.cpp
diff --git a/third_party/WebKit/Source/modules/serviceworkers/FetchEvent.cpp b/third_party/WebKit/Source/modules/serviceworkers/FetchEvent.cpp
index 9d394618e8f5b7ecd4e5e3cf2349167c631688aa..a85cb576360d6ff657feddecbcc436de0fe3ef31 100644
--- a/third_party/WebKit/Source/modules/serviceworkers/FetchEvent.cpp
+++ b/third_party/WebKit/Source/modules/serviceworkers/FetchEvent.cpp
@@ -114,10 +114,13 @@ void FetchEvent::onNavigationPreloadResponse(
     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);