Adds Mojo IDL.

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

Index: third_party/WebKit/Source/core/mojo/MojoReadMessageOptions.idl
diff --git a/third_party/WebKit/Source/core/mojo/MojoReadMessageOptions.idl b/third_party/WebKit/Source/core/mojo/MojoReadMessageOptions.idl
new file mode 100644
index 0000000000000000000000000000000000000000..837bbc3cb824aaa7ead8719ec29bedf803177095
--- /dev/null
+++ b/third_party/WebKit/Source/core/mojo/MojoReadMessageOptions.idl
@@ -0,0 +1,7 @@
+// 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 MojoReadMessageOptions {
+  MojoReadMessageFlags flags;

[jbroman, 2017/01/10 20:46:31]

In JavaScript-land, it would be more idiomatic to have the dictionary be an
optional argument (our bindings will take care of constructing a default
dictionary in this case), and have this have specific fields that correspond to
the flags:

boolean mayDiscard = false;

so that use looks like:

var result = handle.readMessage();
var resultThatMayDiscard = handle.readMessage({ mayDiscard: false });

Doing so reduces the need for numeric constants.

[alokp, 2017/01/11 21:53:02]

Done.

+};