Makes HandleWatcher block until no longer waiting on pipe

mojo/public/cpp/bindings/lib/connector.h

 // Copyright 2013 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_PUBLIC_CPP_BINDINGS_LIB_CONNECTOR_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_CONNECTOR_H_
 
 #include "mojo/public/c/environment/async_waiter.h"
 #include "mojo/public/cpp/bindings/lib/message_queue.h"
 #include "mojo/public/cpp/bindings/message.h"
@@ skipping 67 matching lines @@
   void WaitToReadMore();
 
   // Returns false if |this| was destroyed during message dispatch.
   MOJO_WARN_UNUSED_RESULT bool ReadSingleMessage(MojoResult* read_result);
 
   // |this| can be destroyed during message dispatch.
   void ReadAllAvailableMessages();
 
   void NotifyError();
 
+  // Cancels any calls made to |waiter_|.
+  void CancelWait();
+
   ErrorHandler* error_handler_;
   const MojoAsyncWaiter* waiter_;
 
   ScopedMessagePipeHandle message_pipe_;
   MessageReceiver* incoming_receiver_;
 
   MojoAsyncWaitID async_wait_id_;
   bool error_;
   bool drop_writes_;
   bool enforce_errors_from_incoming_receiver_;
 
   // If non-null, this will be set to true when the Connector is destroyed.  We
   // use this flag to allow for the Connector to be destroyed as a side-effect
   // of dispatching an incoming message.
   bool* destroyed_flag_;
 
   MOJO_DISALLOW_COPY_AND_ASSIGN(Connector);
 };
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_CONNECTOR_H_