Adds sync brokering to Windows EDK

content/public/test/test_mojo_service.mojom

 // Copyright 2015 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.
 
 module content.mojom;
 
 interface TestMojoService {
   // Doesn't actually do anything, just responds.
   DoSomething() => ();
 
   // Terminates the current process to cause a connection error. Meant to test
   // a connection error for the utility process.
   DoTerminateProcess() => ();
 
   // Tries to create a temporary folder. Requires a sandbox to succeed.
   CreateFolder() => (bool succeeded);
 
   // Retrieve the requestor name as seen by the test app providing this service.
   GetRequestorName() => (string name);
+
+  // Requests that a new shared buffer be created and returned. If successful,
+  // |buffer| is non-null and its contents match |message|'s bytes exactly.
+  CreateSharedBuffer(string message) => (handle<shared_buffer>? buffer);
 };