Adds Mojo IDL.

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

Index: third_party/WebKit/Source/core/mojo/Mojo.idl
diff --git a/third_party/WebKit/Source/core/mojo/Mojo.idl b/third_party/WebKit/Source/core/mojo/Mojo.idl
new file mode 100644
index 0000000000000000000000000000000000000000..de649c6426307e69d6afacdadf9f0b272b0ac6a1
--- /dev/null
+++ b/third_party/WebKit/Source/core/mojo/Mojo.idl
@@ -0,0 +1,49 @@
+// Copyright 2016 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.
+
+typedef unsigned long MojoResult;
+typedef unsigned long MojoHandleSignals;
+typedef unsigned long MojoCreateMessagePipeOptionsFlags;
+typedef unsigned long MojoWriteMessageFlags;
+typedef unsigned long MojoReadMessageFlags;
+
+callback MojoWatchCallback = void (MojoResult result);
+
+interface Mojo {
+    const MojoResult RESULT_OK = 0;
+    const MojoResult RESULT_CANCELLED = 1;
+    const MojoResult RESULT_UNKNOWN = 2;
+    const MojoResult RESULT_INVALID_ARGUMENT = 3;
+    const MojoResult RESULT_DEADLINE_EXCEEDED = 4;
+    const MojoResult RESULT_NOT_FOUND = 5;
+    const MojoResult RESULT_ALREADY_EXISTS = 6;
+    const MojoResult RESULT_PERMISSION_DENIED = 7;
+    const MojoResult RESULT_RESOURCE_EXHAUSTED = 8;
+    const MojoResult RESULT_FAILED_PRECONDITION = 9;
+    const MojoResult RESULT_ABORTED = 10;
+    const MojoResult RESULT_OUT_OF_RANGE = 11;
+    const MojoResult RESULT_UNIMPLEMENTED = 12;
+    const MojoResult RESULT_INTERNAL = 13;
+    const MojoResult RESULT_UNAVAILABLE = 14;
+    const MojoResult RESULT_DATA_LOSS = 15;
+    const MojoResult RESULT_BUSY = 16;
+    const MojoResult RESULT_SHOULD_WAIT = 17;
+
+    const MojoHandleSignals HANDLE_SIGNAL_NONE = 0;
+    const MojoHandleSignals HANDLE_SIGNAL_READABLE = 1;
+    const MojoHandleSignals HANDLE_SIGNAL_WRITABLE = 2;
+    const MojoHandleSignals HANDLE_SIGNAL_PEER_CLOSED = 4;
+
+    const MojoCreateMessagePipeOptionsFlags CREATE_MESSAGE_PIPE_OPTIONS_FLAG_NONE = 0;
+    const MojoWriteMessageFlags WRITE_MESSAGE_FLAG_NONE = 0;
+    const MojoReadMessageFlags READ_MESSAGE_FLAG_NONE = 0;
+    const MojoReadMessageFlags READ_MESSAGE_FLAG_MAY_DISCARD = 1;
+
+    [CallWith=ScriptState] unsigned long watch(MojoHandle handle, MojoHandleSignals signals, MojoWatchCallback callback);
+    void cancelWatch(unsigned long watchId);
+
+    MojoCreateMessagePipeResult createMessagePipe(MojoCreateMessagePipeOptions options);
+    MojoResult writeMessage(MojoMessagePipeHandle pipe, ArrayBuffer buffer, sequence<MojoHandle> handles, MojoWriteMessageFlags flags);

[Ken Rockot(use gerrit already), 2016/10/18 15:47:10]

APIs that take ArrayBuffer are sad because then you can only use ArrayBuffer
with them. I believe you want BufferSource instead, as this can be an
ArrayBuffer, or a typed array, or a data view type, etc.

[alokp, 2016/10/18 16:48:36]

I used ArrayBuffer to keep writeMessage consistent with readMessage. I can use
BufferSource if that is preferred.

+    MojoReadMessageResult readMessage(MojoMessagePipeHandle pipe, MojoReadMessageFlags flags);

[Ken Rockot(use gerrit already), 2016/10/18 15:47:10]

Note that we also have new read/write message APIs, and these old ones should be
considered deprecated. The new APIs deal with a Message object type, and message
storage is allocated by the Mojo system on your behalf. This eliminates
otherwise unavoidable redundant copies when using message pipes.

I think it's fine to only achieve parity with the existing JS bindings for now,
but it is probably worth supporting the new APIs as well before switching any
code to use the new core interfaces.

[alokp, 2016/10/18 16:48:36]

Acknowledged.

+};