XMLHttpRequest: return null upon failing responseArrayBuffer allocation.

third_party/WebKit/Source/core/dom/DOMArrayBuffer.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 "core/dom/DOMArrayBuffer.h"
 
 #include "bindings/core/v8/DOMDataStore.h"
+#include "wtf/RefPtr.h"
 
 namespace blink {
 
+DOMArrayBuffer* DOMArrayBuffer::createUninitializedOrNull(
+    unsigned numElements,
+    unsigned elementByteSize) {
+  RefPtr<ArrayBuffer> buffer =
+      WTF::ArrayBuffer::createUninitializedOrNull(numElements, elementByteSize);
+  if (!buffer)
+    return nullptr;
+  return create(std::move(buffer));
+}
+
 v8::Local<v8::Object> DOMArrayBuffer::wrap(
     v8::Isolate* isolate,
     v8::Local<v8::Object> creationContext) {
   DCHECK(!DOMDataStore::containsWrapper(this, isolate));
 
   const WrapperTypeInfo* wrapperTypeInfo = this->wrapperTypeInfo();
   v8::Local<v8::Object> wrapper =
       v8::ArrayBuffer::New(isolate, data(), byteLength());
 
   return associateWithWrapper(isolate, wrapperTypeInfo, wrapper);
 }
 
 }  // namespace blink