[wrapper-tracing] Untangle non-trivial mixin ctors

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 99 matching lines @@
 }
 
 void FetchEvent::onNavigationPreloadResponse(
     std::unique_ptr<WebServiceWorkerResponse> response,
     std::unique_ptr<WebDataConsumerHandle> dataConsumeHandle) {
   if (!m_scriptState->contextIsValid())
     return;
   DCHECK(m_preloadResponseProperty);
   ScriptState::Scope scope(m_scriptState.get());
   FetchResponseData* responseData =
-      FetchResponseData::createWithBuffer(new BodyStreamBuffer(
+      FetchResponseData::createWithBuffer(BodyStreamBuffer::create(
           m_scriptState.get(), new BytesConsumerForDataConsumerHandle(
                                    m_scriptState->getExecutionContext(),
                                    std::move(dataConsumeHandle))));
   responseData->setURL(response->url());
   responseData->setStatus(response->status());
   responseData->setStatusMessage(response->statusText());
   responseData->setResponseTime(response->responseTime());
   for (const auto& header : response->headers())
     responseData->headerList()->append(header.key, header.value);
   FetchResponseData* taintedResponse =
@@ skipping 12 matching lines @@
 }
 
 DEFINE_TRACE(FetchEvent) {
   visitor->trace(m_observer);
   visitor->trace(m_request);
   visitor->trace(m_preloadResponseProperty);
   ExtendableEvent::trace(visitor);
 }
 
 }  // namespace blink