Support Closure in ALL the loops!

base/message_loop_proxy.h

 // Copyright (c) 2011 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_MESSAGE_LOOP_PROXY_H_
 #define BASE_MESSAGE_LOOP_PROXY_H_
 #pragma once
 
 #include "base/base_api.h"
 #include "base/basictypes.h"
+#include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/task.h"
 
 namespace base {
 
 struct MessageLoopProxyTraits;
 
 // This class provides a thread-safe refcounted interface to the Post* methods
 // of a message loop. This class can outlive the target message loop. You can
 // obtain a MessageLoopProxy via Thread::message_loop_proxy() or
 // MessageLoopProxy::CreateForCurrentThread().
 class BASE_API MessageLoopProxy
     : public base::RefCountedThreadSafe<MessageLoopProxy,
                                         MessageLoopProxyTraits> {
  public:
   // These methods are the same as in message_loop.h, but are guaranteed to
   // either post the Task to the MessageLoop (if it's still alive), or to
   // delete the Task otherwise.
   // They return true iff the thread existed and the task was posted.  Note that
   // even if the task is posted, there's no guarantee that it will run; for
   // example the target loop may already be quitting, or in the case of a
   // delayed task a Quit message may preempt it in the message loop queue.
   // Conversely, a return value of false is a guarantee the task will not run.
   virtual bool PostTask(const tracked_objects::Location& from_here,
                         Task* task) = 0;
   virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
-                               Task* task, int64 delay_ms) = 0;
+                               Task* task,
+                               int64 delay_ms) = 0;
   virtual bool PostNonNestableTask(const tracked_objects::Location& from_here,
                                    Task* task) = 0;
   virtual bool PostNonNestableDelayedTask(
       const tracked_objects::Location& from_here,
       Task* task,
       int64 delay_ms) = 0;
+
+  // TODO(ajwong): Remove the functions above once the Task -> Closure migration
+  // is complete.
+  //
+  // There are 2 sets of Post*Task functions, one which takes the older Task*
+  // function object representation, and one that takes the newer base::Closure.
+  // We have this overload to allow a staged transition between the two systems.
+  // Once the transition is done, the functions above should be deleted.
+  virtual bool PostTask(const tracked_objects::Location& from_here,
+                        const base::Closure& task) = 0;
+  virtual bool PostDelayedTask(const tracked_objects::Location& from_here,
+                               const base::Closure& task,
+                               int64 delay_ms) = 0;
+  virtual bool PostNonNestableTask(const tracked_objects::Location& from_here,
+                                   const base::Closure& task) = 0;
+  virtual bool PostNonNestableDelayedTask(
+      const tracked_objects::Location& from_here,
+      const base::Closure& task,
+      int64 delay_ms) = 0;
+
   // A method which checks if the caller is currently running in the thread that
   // this proxy represents.
   virtual bool BelongsToCurrentThread() = 0;
 
   template <class T>
   bool DeleteSoon(const tracked_objects::Location& from_here,
                   T* object) {
     return PostNonNestableTask(from_here, new DeleteTask<T>(object));
   }
   template <class T>
@@ skipping 20 matching lines @@
 
 struct MessageLoopProxyTraits {
   static void Destruct(const MessageLoopProxy* proxy) {
     proxy->OnDestruct();
   }
 };
 
 }  // namespace base
 
 #endif  // BASE_MESSAGE_LOOP_PROXY_H_