Fix race on mojo message pump shutdown.

mojo/message_pump/message_pump_mojo.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_MESSAGE_PUMP_MESSAGE_PUMP_MOJO_H_
 #define MOJO_MESSAGE_PUMP_MESSAGE_PUMP_MOJO_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <set>
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_pump.h"
 #include "base/observer_list.h"
 #include "base/synchronization/lock.h"
+#include "base/synchronization/waitable_event.h"
 #include "base/time/time.h"
 #include "mojo/message_pump/mojo_message_pump_export.h"
 #include "mojo/public/cpp/system/core.h"
 
 namespace mojo {
 namespace common {
 
 class MessagePumpMojoHandler;
 
 // Mojo implementation of MessagePump.
@@ skipping 58 matching lines @@
   typedef std::map<Handle, Handler> HandleToHandler;
 
   // Implementation of Run().
   void DoRunLoop(RunState* run_state, Delegate* delegate);
 
   // Services the set of handles ready. If |block| is true this waits for a
   // handle to become ready, otherwise this does not block. Returns |true| if a
   // handle has become ready, |false| otherwise.
   bool DoInternalWork(const RunState& run_state, bool block);
 
+  bool DoNonMojoWork(const RunState& run_state, bool block);
+
   // Waits for handles in the wait set to become ready. Returns |true| if ready
   // handles may be available, or |false| if the wait's deadline was exceeded.
   // Note, ready handles may be unavailable, even though |true| was returned.
   bool WaitForReadyHandles(const RunState& run_state) const;
 
   // Retrieves any 'ready' handles from the wait set, and runs the handler's
   // OnHandleReady() or OnHandleError() functions as necessary. Returns |true|
   // if any handles were ready and processed.
   bool ProcessReadyHandles();
 
@@ skipping 41 matching lines @@
   int next_handler_id_;
 
   base::ObserverList<Observer> observers_;
 
   // Mojo handle for the wait set.
   ScopedHandle wait_set_handle_;
   // Used to wake up run loop from |SignalControlPipe()|.
   ScopedMessagePipeHandle read_handle_;
   ScopedMessagePipeHandle write_handle_;
 
+  // Used to sleep until there is more work to do, when the Mojo EDK is shutting
+  // down.
+  base::WaitableEvent event_;
+
   DISALLOW_COPY_AND_ASSIGN(MessagePumpMojo);
 };
 
 }  // namespace common
 }  // namespace mojo
 
 #endif  // MOJO_MESSAGE_PUMP_MESSAGE_PUMP_MOJO_H_