Revert "Revert "Const-ify RefCountedThreadSafe::AddRef and Release.""

chrome/browser/browser_thread.h

 // Copyright (c) 2010 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 CHROME_BROWSER_BROWSER_THREAD_H_
 #define CHROME_BROWSER_BROWSER_THREAD_H_
 #pragma once
 
 #include "base/lock.h"
 #include "base/task.h"
@@ skipping 91 matching lines @@
                                   Task* task);
   static bool PostNonNestableDelayedTask(
       ID identifier,
       const tracked_objects::Location& from_here,
       Task* task,
       int64 delay_ms);
 
   template <class T>
   static bool DeleteSoon(ID identifier,
                          const tracked_objects::Location& from_here,
-                         T* object) {
+                         const T* object) {
     return PostNonNestableTask(
         identifier, from_here, new DeleteTask<T>(object));
   }
 
   template <class T>
   static bool ReleaseSoon(ID identifier,
                           const tracked_objects::Location& from_here,
-                          T* object) {
+                          const T* object) {
     return PostNonNestableTask(
         identifier, from_here, new ReleaseTask<T>(object));
   }
 
   // Callable on any thread.  Returns whether the given ID corresponds to a well
   // known thread.
   static bool IsWellKnownThread(ID identifier);
 
   // Callable on any thread.  Returns whether you're currently on a particular
   // thread.
@@ skipping 16 matching lines @@
   // Use these templates in conjuction with RefCountedThreadSafe when you want
   // to ensure that an object is deleted on a specific thread.  This is needed
   // when an object can hop between threads (i.e. IO -> FILE -> IO), and thread
   // switching delays can mean that the final IO tasks executes before the FILE
   // task's stack unwinds.  This would lead to the object destructing on the
   // FILE thread, which often is not what you want (i.e. to unregister from
   // NotificationService, to notify other objects on the creating thread etc).
   template<ID thread>
   struct DeleteOnThread {
     template<typename T>
-    static void Destruct(T* x) {
+    static void Destruct(const T* x) {
       if (CurrentlyOn(thread)) {
         delete x;
       } else {
         DeleteSoon(thread, FROM_HERE, x);
       }
     }
   };
 
   // Sample usage:
   // class Foo
@@ skipping 32 matching lines @@
   static Lock lock_;
 
   // An array of the BrowserThread objects.  This array is protected by |lock_|.
   // The threads are not owned by this array.  Typically, the threads are owned
   // on the UI thread by the g_browser_process object.  BrowserThreads remove
   // themselves from this array upon destruction.
   static BrowserThread* browser_threads_[ID_COUNT];
 };
 
 #endif  // CHROME_BROWSER_BROWSER_THREAD_H_