Implements JS bindings for mojo shared buffer.

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

 // 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 MojoHandle_h
 #define MojoHandle_h
 
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "mojo/public/cpp/system/core.h"
 
 namespace blink {
 
 class ArrayBufferOrArrayBufferView;
 class MojoHandleSignals;
+class MojoMapBufferResult;
 class MojoReadMessageFlags;
 class MojoReadMessageResult;
 class MojoWatchCallback;
 class MojoWatcher;
 class ScriptState;
 
 class MojoHandle final : public GarbageCollectedFinalized<MojoHandle>,
                          public ScriptWrappable {
   DEFINE_WRAPPERTYPEINFO();
 
  public:
   CORE_EXPORT static MojoHandle* create(mojo::ScopedHandle);
 
   void close();
   MojoWatcher* watch(ScriptState*,
                      const MojoHandleSignals&,
                      MojoWatchCallback*);
+
+  // MessagePipe handle.
   MojoResult writeMessage(ArrayBufferOrArrayBufferView&,
                           const HeapVector<Member<MojoHandle>>&);
   void readMessage(const MojoReadMessageFlags&, MojoReadMessageResult&);
 
+  // SharedBuffer handle.
+  void mapBuffer(unsigned offset, unsigned numBytes, MojoMapBufferResult&);
+
   DEFINE_INLINE_TRACE() {}
 
  private:
   explicit MojoHandle(mojo::ScopedHandle);
 
   mojo::ScopedHandle m_handle;
 };
 
 }  // namespace blink
 
 #endif  // MojoHandle_h