Change BodyStreamBuffer to be FetchDataConsumerHandle-based and enable backpressure in Fetch API

Source/modules/fetch/FetchResponseDataTest.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/fetch/FetchResponseData.h"
 
+#include "core/dom/DOMArrayBuffer.h"
 #include "modules/fetch/FetchHeaderList.h"
 #include "platform/blob/BlobData.h"
 #include "public/platform/WebServiceWorkerResponse.h"
 
 #include <gtest/gtest.h>
 
 namespace blink {
 
 class FetchResponseDataTest : public ::testing::Test {
 public:
@@ skipping 53 matching lines @@
     WebServiceWorkerResponse webResponse;
     FetchResponseData* internalResponse = createInternalResponse();
     FetchResponseData* opaqueResponseData = internalResponse->createOpaqueFilteredResponse();
 
     opaqueResponseData->populateWebServiceWorkerResponse(webResponse);
     EXPECT_EQ(WebServiceWorkerResponseTypeOpaque, webResponse.responseType());
     CheckHeaders(webResponse);
 }
 
 } // namespace WebCore