content/child: Remove use of MessageLoopProxy and deprecated MessageLoop APIs

ppapi/proxy/proxy_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 PPAPI_PROXY_PROXY_CHANNEL_H_
 #define PPAPI_PROXY_PROXY_CHANNEL_H_
 
 #include "base/files/scoped_file.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/process/process.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_platform_file.h"
 #include "ipc/ipc_sender.h"
 #include "ipc/ipc_sync_channel.h"
 #include "ppapi/proxy/ppapi_proxy_export.h"
 
 namespace base {
-class MessageLoopProxy;
+class SingleThreadTaskRunner;
 class WaitableEvent;
 }
 
 namespace IPC {
 class TestSink;
 }
 
 namespace ppapi {
 namespace proxy {
 
 class PPAPI_PROXY_EXPORT ProxyChannel
     : public IPC::Listener,
       public IPC::Sender {
  public:
   class PPAPI_PROXY_EXPORT Delegate {
    public:
     virtual ~Delegate() {}
 
-    // Returns the dedicated message loop for processing IPC requests.
-    virtual base::MessageLoopProxy* GetIPCMessageLoop() = 0;
+    // Returns the task runner for processing IPC requests.
+    virtual base::SingleThreadTaskRunner* GetIPCTaskRunner() = 0;
 
     // Returns the event object that becomes signalled when the main thread's
     // message loop exits.
     virtual base::WaitableEvent* GetShutdownEvent() = 0;
 
     // Duplicates a handle to the provided object, returning one that is valid
     // on the other side of the channel. This is part of the delegate interface
     // because both sides of the channel may not have sufficient permission to
     // duplicate handles directly. The implementation must provide the same
     // guarantees as ProxyChannel::ShareHandleWithRemote below.
@@ skipping 69 matching lines @@
   // remote side has crashed.
   scoped_ptr<IPC::SyncChannel> channel_;
 
   DISALLOW_COPY_AND_ASSIGN(ProxyChannel);
 };
 
 }  // namespace proxy
 }  // namespace ppapi
 
 #endif  // PPAPI_PROXY_PROXY_CHANNEL_H_