Adds Mojo IDL.

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

Index: third_party/WebKit/Source/core/mojo/MojoCreateMessagePipeResult.idl
diff --git a/third_party/WebKit/Source/modules/push_messaging/PushSubscriptionOptionsInit.idl b/third_party/WebKit/Source/core/mojo/MojoCreateMessagePipeResult.idl
similarity index 56%
copy from third_party/WebKit/Source/modules/push_messaging/PushSubscriptionOptionsInit.idl
copy to third_party/WebKit/Source/core/mojo/MojoCreateMessagePipeResult.idl
index 720101854ed1653d3621a18d4d5f337656084ae0..88da590053979f807d27fa4fa0b2ad9d10eb6a0e 100644
--- a/third_party/WebKit/Source/modules/push_messaging/PushSubscriptionOptionsInit.idl
+++ b/third_party/WebKit/Source/core/mojo/MojoCreateMessagePipeResult.idl
@@ -2,9 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// https://w3c.github.io/push-api/#idl-def-PushSubscriptionOptionsInit
-
-dictionary PushSubscriptionOptionsInit {
-    boolean userVisibleOnly = false;
-    BufferSource? applicationServerKey = null;
+dictionary MojoCreateMessagePipeResult {
+  // TODO(alokp): Consider raising exception for error.
+  required MojoResult result;
+  MojoMessagePipeHandle handle0;
+  MojoMessagePipeHandle handle1;
 };