XMLHttpRequest: return null upon failing responseArrayBuffer allocation.

third_party/WebKit/Source/core/mojo/MojoHandle.cpp

 // Copyright 2017 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/mojo/MojoHandle.h"
 
 #include "bindings/core/v8/ArrayBufferOrArrayBufferView.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMArrayBufferView.h"
@@ skipping 58 matching lines @@
     flags |= MOJO_READ_MESSAGE_FLAG_MAY_DISCARD;
 
   uint32_t numBytes = 0, numHandles = 0;
   MojoResult result = MojoReadMessage(m_handle->value(), nullptr, &numBytes,
                                       nullptr, &numHandles, flags);
   if (result != MOJO_RESULT_RESOURCE_EXHAUSTED) {
     resultDict.setResult(result);
     return;
   }
 
-  DOMArrayBuffer* buffer = DOMArrayBuffer::createUninitialized(numBytes, 1);
+  DOMArrayBuffer* buffer =
+      DOMArrayBuffer::createUninitializedOrNull(numBytes, 1);
+  CHECK(buffer);
   Vector<::MojoHandle, kHandleVectorInlineCapacity> rawHandles(numHandles);
   result = MojoReadMessage(m_handle->value(), buffer->data(), &numBytes,
                            rawHandles.data(), &numHandles, flags);
 
   HeapVector<Member<MojoHandle>> handles(numHandles);
   for (size_t i = 0; i < numHandles; ++i) {
     handles[i] =
         MojoHandle::create(mojo::MakeScopedHandle(mojo::Handle(rawHandles[i])));
   }
 
   resultDict.setResult(result);
   resultDict.setBuffer(buffer);
   resultDict.setHandles(handles);
 }
 
 }  // namespace blink