XMLHttpRequest: return null upon failing responseArrayBuffer allocation.

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

Index: third_party/WebKit/Source/core/dom/DOMArrayBuffer.cpp
diff --git a/third_party/WebKit/Source/core/dom/DOMArrayBuffer.cpp b/third_party/WebKit/Source/core/dom/DOMArrayBuffer.cpp
index 67e9324cc957ba86ef187cbbfb8906c97b3ca656..9a5aabfde8c68288b480d7859d8dfb52fcd4d657 100644
--- a/third_party/WebKit/Source/core/dom/DOMArrayBuffer.cpp
+++ b/third_party/WebKit/Source/core/dom/DOMArrayBuffer.cpp
@@ -5,9 +5,20 @@
 #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) {