Simplify SyncChannel message pumping event

ipc/ipc_sync_channel.h

 // Copyright (c) 2012 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 IPC_IPC_SYNC_CHANNEL_H_
 #define IPC_IPC_SYNC_CHANNEL_H_
 
 #include <deque>
 #include <memory>
 #include <string>
@@ skipping 193 matching lines @@
 
     scoped_refptr<ReceivedSyncMsgQueue> received_sync_msgs_;
 
     base::WaitableEvent* shutdown_event_;
     base::WaitableEventWatcher shutdown_watcher_;
     base::WaitableEventWatcher::EventCallback shutdown_watcher_callback_;
     int restrict_dispatch_group_;
   };
 
  private:
-  class PumpMessagesEvent;
-
   SyncChannel(
       Listener* listener,
       const scoped_refptr<base::SingleThreadTaskRunner>& ipc_task_runner,
       base::WaitableEvent* shutdown_event);
 
   void OnDispatchHandleReady(MojoResult result);
 
   SyncContext* sync_context() {
     return reinterpret_cast<SyncContext*>(context());
   }
 
   // Both these functions wait for a reply, timeout or process shutdown.  The
   // latter one also runs a nested message loop in the meantime.
   static void WaitForReply(mojo::SyncHandleRegistry* registry,
                            SyncContext* context,
-                           const MojoEvent* pump_messages_event);
+                           bool pump_messages);
 
   // Runs a nested message loop until a reply arrives, times out, or the process
   // shuts down.
   static void WaitForReplyWithNestedMessageLoop(SyncContext* context);
 
   // Starts the dispatch watcher.
   void StartWatching();
 
   // ChannelProxy overrides:
   void OnChannelInit() override;
 
-  scoped_refptr<PumpMessagesEvent> pump_messages_event_;
   scoped_refptr<mojo::SyncHandleRegistry> sync_handle_registry_;
 
   // Used to signal events between the IPC and listener threads.
   mojo::Watcher dispatch_watcher_;
 
   // Tracks SyncMessageFilters created before complete channel initialization.
   std::vector<scoped_refptr<SyncMessageFilter>> pre_init_sync_message_filters_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncChannel);
 };
 
 }  // namespace IPC
 
 #endif  // IPC_IPC_SYNC_CHANNEL_H_