Const-ify RefCountedThreadSafe::AddRef and Release.

base/task.h

Index: base/task.h
diff --git a/base/task.h b/base/task.h
index e6ac33c6f27a81f40e47fdbe11ad8e264ed8f544..28d15fcadf551e96e9aaa9f69a2b26551c9c3ba5 100644
--- a/base/task.h
+++ b/base/task.h
@@ -180,7 +180,7 @@ class ScopedRunnableMethodFactory {
 template<class T>
 class DeleteTask : public CancelableTask {
  public:
-  explicit DeleteTask(T* obj) : obj_(obj) {
+  explicit DeleteTask(const T* obj) : obj_(obj) {
   }
   virtual void Run() {
     delete obj_;
@@ -190,14 +190,14 @@ class DeleteTask : public CancelableTask {
   }
 
  private:
-  T* obj_;
+  const T* obj_;
 };
 
 // Task to Release() an object
 template<class T>
 class ReleaseTask : public CancelableTask {
  public:
-  explicit ReleaseTask(T* obj) : obj_(obj) {
+  explicit ReleaseTask(const T* obj) : obj_(obj) {
   }
   virtual void Run() {
     if (obj_)
@@ -208,7 +208,7 @@ class ReleaseTask : public CancelableTask {
   }
 
  private:
-  T* obj_;
+  const T* obj_;
 };
 
 // RunnableMethodTraits --------------------------------------------------------