Remove all remaining traces of MessageLoopProxy.

net/url_request/url_request_context_getter.cc

 // 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.
 
 #include "net/url_request/url_request_context_getter.h"
 
 #include "base/debug/leak_annotations.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "net/url_request/url_request_context.h"
@@ skipping 29 matching lines @@
         // Can't force-delete the object here, because some derived classes
         // can only be deleted on the owning thread, so just emit a warning to
         // aid in debugging.
         DLOG(WARNING) << "URLRequestContextGetter leaking due to no owning"
                       << " thread.";
         // Let LSan know we know this is a leak. https://crbug.com/594130
         ANNOTATE_LEAKING_OBJECT_PTR(this);
       }
     }
   }
-  // If no IO message loop proxy was available, we will just leak memory.
+  // If no IO task runner was available, we will just leak memory.
   // This is also true if the IO thread is gone.
 }
 
 void URLRequestContextGetter::NotifyContextShuttingDown() {
   DCHECK(GetNetworkTaskRunner()->BelongsToCurrentThread());
 
   // Once shutdown starts, this must always return NULL.
   DCHECK(!GetURLRequestContext());
 
   FOR_EACH_OBSERVER(URLRequestContextGetterObserver, observer_list_,
@@ skipping 12 matching lines @@
   return context_;
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>
 TrivialURLRequestContextGetter::GetNetworkTaskRunner() const {
   return main_task_runner_;
 }
 
 
 }  // namespace net