Implements JS bindings for mojo shared buffer.

third_party/WebKit/Source/core/mojo/MojoSharedBuffer.h

Index: third_party/WebKit/Source/core/mojo/MojoSharedBuffer.h
diff --git a/third_party/WebKit/Source/core/mojo/MojoSharedBuffer.h b/third_party/WebKit/Source/core/mojo/MojoSharedBuffer.h
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+// 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.
+
+#ifndef MojoSharedBuffer_h
+#define MojoSharedBuffer_h
+
+#include "bindings/core/v8/ScriptWrappable.h"
+
+namespace blink {
+
+class DOMArrayBuffer;
+
+class MojoSharedBuffer final
+    : public GarbageCollectedFinalized<MojoSharedBuffer>,
+      public ScriptWrappable {
+  DEFINE_WRAPPERTYPEINFO();
+
+ public:
+  MojoSharedBuffer(void* data, unsigned numBytes);
+
+  DOMArrayBuffer* buffer() { return m_buffer.get(); }
+  void unmap();
+
+  DECLARE_TRACE();
+
+ private:
+  Member<DOMArrayBuffer> m_buffer;
+};
+
+}  // namespace blink
+
+#endif  // MojoSharedBuffer_h