Add embedder::AsyncWait()

mojo/edk/embedder/embedder.h

 // Copyright 2014 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.
 
 #ifndef MOJO_EDK_EMBEDDER_EMBEDDER_H_
 #define MOJO_EDK_EMBEDDER_EMBEDDER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 99 matching lines @@
 MOJO_SYSTEM_IMPL_EXPORT MojoResult
 CreatePlatformHandleWrapper(ScopedPlatformHandle platform_handle,
                             MojoHandle* platform_handle_wrapper_handle);
 // Retrieves the |PlatformHandle| that was wrapped into a |MojoHandle| (using
 // |CreatePlatformHandleWrapper()| above). Note that the |MojoHandle| must still
 // be closed separately.
 MOJO_SYSTEM_IMPL_EXPORT MojoResult
 PassWrappedPlatformHandle(MojoHandle platform_handle_wrapper_handle,
                           ScopedPlatformHandle* platform_handle);
 
+// Start waiting the handle asynchronously. On success, |callback| will be
+// called exactly once, when |handle| satisfies a signal in |signals| or it
+// becomes known that it will never do so. |callback| will be executed on an
+// arbitrary thread. It must not call any Mojo system or embedder functions.
+MOJO_SYSTEM_IMPL_EXPORT MojoResult
+AsyncWait(MojoHandle handle,
+          MojoHandleSignals signals,
+          base::Callback<void(MojoResult)> callback);
+
 }  // namespace embedder
 }  // namespace mojo
 
 #endif  // MOJO_EDK_EMBEDDER_EMBEDDER_H_