Reduce usage of MessageLoopProxy in base/

base/observer_list_threadsafe.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 BASE_OBSERVER_LIST_THREADSAFE_H_
 #define BASE_OBSERVER_LIST_THREADSAFE_H_
 
 #include <algorithm>
 #include <map>
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/message_loop/message_loop.h"
-#include "base/message_loop/message_loop_proxy.h"
 #include "base/observer_list.h"
+#include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
+#include "base/thread_task_runner_handle.h"
 #include "base/threading/platform_thread.h"
 
 ///////////////////////////////////////////////////////////////////////////////
 //
 // OVERVIEW:
 //
 //   A thread-safe container for a list of observers.
 //   This is similar to the observer_list (see observer_list.h), but it
 //   is more robust for multi-threaded situations.
 //
@@ skipping 171 matching lines @@
   }
 
   // TODO(mbelshe):  Add more wrappers for Notify() with more arguments.
 
  private:
   // See comment above ObserverListThreadSafeTraits' definition.
   friend struct ObserverListThreadSafeTraits<ObserverType>;
 
   struct ObserverListContext {
     explicit ObserverListContext(NotificationType type)
-        : loop(base::MessageLoopProxy::current()),
-          list(type) {
-    }
+        : task_runner(base::ThreadTaskRunnerHandle::Get()), list(type) {}
 
-    scoped_refptr<base::MessageLoopProxy> loop;
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner;
     ObserverList<ObserverType> list;
 
     DISALLOW_COPY_AND_ASSIGN(ObserverListContext);
   };
 
   ~ObserverListThreadSafe() {
     STLDeleteValues(&observer_lists_);
   }
 
   template <class Method, class Params>
   void Notify(const UnboundMethod<ObserverType, Method, Params>& method) {
     base::AutoLock lock(list_lock_);
     typename ObserversListMap::iterator it;
     for (it = observer_lists_.begin(); it != observer_lists_.end(); ++it) {
       ObserverListContext* context = (*it).second;
-      context->loop->PostTask(
+      context->task_runner->PostTask(
           FROM_HERE,
-          base::Bind(&ObserverListThreadSafe<ObserverType>::
-              template NotifyWrapper<Method, Params>, this, context, method));
+          base::Bind(&ObserverListThreadSafe<
+                         ObserverType>::template NotifyWrapper<Method, Params>,
+                     this,
+                     context,
+                     method));
     }
   }
 
   // Wrapper which is called to fire the notifications for each thread's
   // ObserverList.  This function MUST be called on the thread which owns
   // the unsafe ObserverList.
   template <class Method, class Params>
   void NotifyWrapper(ObserverListContext* context,
       const UnboundMethod<ObserverType, Method, Params>& method) {
 
     // Check that this list still needs notifications.
     {
       base::AutoLock lock(list_lock_);
       typename ObserversListMap::iterator it =
           observer_lists_.find(base::PlatformThread::CurrentId());
 
       // The ObserverList could have been removed already.  In fact, it could
-      // have been removed and then re-added!  If the master list's loop
+      // have been removed and then re-added!  If the master list's task runner
       // does not match this one, then we do not need to finish this
       // notification.
       if (it == observer_lists_.end() || it->second != context)
         return;
     }
 
     {
       typename ObserverList<ObserverType>::Iterator it(context->list);
       ObserverType* obs;
       while ((obs = it.GetNext()) != NULL)
@@ skipping 23 matching lines @@
       ObserversListMap;
 
   mutable base::Lock list_lock_;  // Protects the observer_lists_.
   ObserversListMap observer_lists_;
   const NotificationType type_;
 
   DISALLOW_COPY_AND_ASSIGN(ObserverListThreadSafe);
 };
 
 #endif  // BASE_OBSERVER_LIST_THREADSAFE_H_