Implements JS bindings for mojo shared buffer.

third_party/WebKit/Source/core/mojo/MojoCreateSharedBufferResult.idl

+// 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.
+
+dictionary MojoCreateSharedBufferResult {
+    required MojoResult result;

[yzshen1, 2017/03/01 23:11:46]

nit: I notice that in some files the indent is 4-space while in the others it is
2-space.

[alokp, 2017/03/01 23:58:34]

jbroman: What is the convention here? I remember reading somewhere that idl
files need to have 4 space indents?

[alokp, 2017/03/02 18:55:32]

I found the page which specifies 4-space indents and fixed this patch to make
the indenting consistent.
https://www.chromium.org/blink/webidl#TOC-Style

+    MojoHandle handle;
+};