XMLHttpRequest: return null upon failing responseArrayBuffer allocation.

third_party/WebKit/Source/core/dom/DOMArrayBuffer.h

 // 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.
 
 #ifndef DOMArrayBuffer_h
 #define DOMArrayBuffer_h
 
 #include "core/CoreExport.h"
 #include "core/dom/DOMArrayBufferBase.h"
 #include "wtf/typed_arrays/ArrayBuffer.h"
@@ skipping 13 matching lines @@
   }
   static DOMArrayBuffer* create(const void* source, unsigned byteLength) {
     return create(WTF::ArrayBuffer::create(source, byteLength));
   }
   static DOMArrayBuffer* create(WTF::ArrayBufferContents& contents) {
     return create(WTF::ArrayBuffer::create(contents));
   }
 
   // Only for use by XMLHttpRequest::responseArrayBuffer and
   // Internals::serializeObject.
-  static DOMArrayBuffer* createUninitialized(unsigned numElements,
-                                             unsigned elementByteSize) {
-    return create(
-        WTF::ArrayBuffer::createUninitialized(numElements, elementByteSize));
-  }
+  static DOMArrayBuffer* createUninitializedOrNull(unsigned numElements,
+                                                   unsigned elementByteSize);
 
   DOMArrayBuffer* slice(int begin, int end) const {
     return create(buffer()->slice(begin, end));
   }
   DOMArrayBuffer* slice(int begin) const {
     return create(buffer()->slice(begin));
   }
 
   v8::Local<v8::Object> wrap(v8::Isolate*,
                              v8::Local<v8::Object> creationContext) override;
 
  private:
   explicit DOMArrayBuffer(PassRefPtr<WTF::ArrayBuffer> buffer)
       : DOMArrayBufferBase(std::move(buffer)) {}
 };
 
 }  // namespace blink
 
 #endif  // DOMArrayBuffer_h