Revert of content/common: Remove use of MessageLoopProxy and deprecated MessageLoop APIs

content/common/gpu/client/gpu_channel_host.h

Index: content/common/gpu/client/gpu_channel_host.h
diff --git a/content/common/gpu/client/gpu_channel_host.h b/content/common/gpu/client/gpu_channel_host.h
index 4ec2e06d2bdad744da832c4d4f674128192835ca..ea1b6b8cd36bf84153f1ff003d210948d2faf58f 100644
--- a/content/common/gpu/client/gpu_channel_host.h
+++ b/content/common/gpu/client/gpu_channel_host.h
@@ -35,6 +35,7 @@
 
 namespace base {
 class MessageLoop;
+class MessageLoopProxy;
 class WaitableEvent;
 }
 
@@ -60,7 +61,7 @@
   ~GpuListenerInfo();
 
   base::WeakPtr<IPC::Listener> listener;
-  scoped_refptr<base::SingleThreadTaskRunner> task_runner;
+  scoped_refptr<base::MessageLoopProxy> loop;
 };
 
 struct ProxyFlushInfo {
@@ -79,8 +80,7 @@
   virtual ~GpuChannelHostFactory() {}
 
   virtual bool IsMainThread() = 0;
-  virtual scoped_refptr<base::SingleThreadTaskRunner>
-  GetIOThreadTaskRunner() = 0;
+  virtual scoped_refptr<base::MessageLoopProxy> GetIOLoopProxy() = 0;
   virtual scoped_ptr<base::SharedMemory> AllocateSharedMemory(size_t size) = 0;
   virtual CreateCommandBufferResult CreateViewCommandBuffer(
       int32 surface_id,
@@ -207,7 +207,7 @@
     // Called on the IO thread.
     void AddRoute(int route_id,
                   base::WeakPtr<IPC::Listener> listener,
-                  scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+                  scoped_refptr<base::MessageLoopProxy> loop);
     // Called on the IO thread.
     void RemoveRoute(int route_id);