[SharedArrayBuffer] Add "AllowShared" extended attribute, used for WebGL

third_party/WebKit/Source/core/geometry/DOMMatrixReadOnly.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 DOMMatrixReadOnly_h
 #define DOMMatrixReadOnly_h
 
 #include <memory>
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptWrappable.h"
+#include "core/dom/ArrayBufferViewHelpers.h"
 #include "core/dom/DOMTypedArray.h"
-#include "core/dom/NotShared.h"
 #include "platform/heap/Handle.h"
 #include "platform/transforms/TransformationMatrix.h"
 
 namespace blink {
 
 class DOMMatrix;
 class DOMMatrixInit;
 class DOMPoint;
 class DOMPointInit;
 
@@ skipping 111 matching lines @@
   // supports 16-byte alignment but Oilpan doesn't. So we use an std::unique_ptr
   // to allocate TransformationMatrix on PartitionAlloc.
   // TODO(oilpan): Oilpan should support 16-byte aligned allocations.
   std::unique_ptr<TransformationMatrix> matrix_;
   bool is2d_;
 };
 
 }  // namespace blink
 
 #endif