Mojo: cancel pending AsyncWait calls when the callers thread exits

mojo/common/handle_watcher.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_COMMON_HANDLE_WATCHER_H_
 #define MOJO_COMMON_HANDLE_WATCHER_H_
 
 #include "base/basictypes.h"
 #include "base/callback_forward.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 15 matching lines @@
 // when the handle is ready, or the deadline has expired.
 class MOJO_COMMON_EXPORT HandleWatcher {
  public:
   HandleWatcher();
   ~HandleWatcher();
 
   // Starts listening for |handle|. This implicitly invokes Stop(). In other
   // words, Start() performs one asynchronous watch at a time. It is ok to call
   // Start() multiple times, but it cancels any existing watches. |callback| is
   // notified when the handle is ready, invalid or deadline has passed and is
-  // notified on the thread Start() was invoked on.
+  // notified on the thread Start() was invoked on. If the current thread exits
+  // before the handle is ready, then |callback| is invoked with a result of
+  // MOJO_RESULT_ABORTED.
   void Start(const Handle& handle,
              MojoWaitFlags wait_flags,
              MojoDeadline deadline,
              const base::Callback<void(MojoResult)>& callback);
 
   // Stops listening. Does nothing if not in the process of listening.
   void Stop();
 
  private:
-  struct StartState;
-
-  // See description of |StartState::weak_factory| for details.
-  void OnHandleReady(MojoResult result);
+  struct State;
 
   // If non-NULL Start() has been invoked.
-  scoped_ptr<StartState> start_state_;
+  scoped_ptr<State> state_;
 
   DISALLOW_COPY_AND_ASSIGN(HandleWatcher);
 };
 
 }  // namespace common
 }  // namespace mojo
 
 #endif  // MOJO_COMMON_HANDLE_WATCHER_H_