Change the ScopedRunnableMethodFactory to use CancelableTasks so that...

base/task.h

Index: base/task.h
===================================================================
--- base/task.h	(revision 40643)
+++ base/task.h	(working copy)
@@ -83,25 +83,26 @@
   }
 
   template <class Method>
-  inline Task* NewRunnableMethod(Method method) {
+  inline CancelableTask* NewRunnableMethod(Method method) {
     return new RunnableMethod<Method, Tuple0>(
         weak_factory_.GetWeakPtr(), method, MakeTuple());
   }
 
   template <class Method, class A>
-  inline Task* NewRunnableMethod(Method method, const A& a) {
+  inline CancelableTask* NewRunnableMethod(Method method, const A& a) {
     return new RunnableMethod<Method, Tuple1<A> >(
         weak_factory_.GetWeakPtr(), method, MakeTuple(a));
   }
 
   template <class Method, class A, class B>
-  inline Task* NewRunnableMethod(Method method, const A& a, const B& b) {
+  inline CancelableTask* NewRunnableMethod(Method method, const A& a,
+                                           const B& b) {
     return new RunnableMethod<Method, Tuple2<A, B> >(
         weak_factory_.GetWeakPtr(), method, MakeTuple(a, b));
   }
 
   template <class Method, class A, class B, class C>
-  inline Task* NewRunnableMethod(Method method,
+  inline CancelableTask* NewRunnableMethod(Method method,
                                  const A& a,
                                  const B& b,
                                  const C& c) {
@@ -110,7 +111,7 @@
   }
 
   template <class Method, class A, class B, class C, class D>
-  inline Task* NewRunnableMethod(Method method,
+  inline CancelableTask* NewRunnableMethod(Method method,
                                  const A& a,
                                  const B& b,
                                  const C& c,
@@ -120,7 +121,7 @@
   }
 
   template <class Method, class A, class B, class C, class D, class E>
-  inline Task* NewRunnableMethod(Method method,
+  inline CancelableTask* NewRunnableMethod(Method method,
                                  const A& a,
                                  const B& b,
                                  const C& c,
@@ -136,9 +137,10 @@
 
  protected:
   template <class Method, class Params>
-  class RunnableMethod : public Task {
+  class RunnableMethod : public CancelableTask {
    public:
-    RunnableMethod(const base::WeakPtr<T>& obj, Method meth, const Params& params)
+    RunnableMethod(const base::WeakPtr<T>& obj, Method meth,
+                   const Params& params)
         : obj_(obj),
           meth_(meth),
           params_(params) {
@@ -151,6 +153,10 @@
         DispatchToMethod(obj_.get(), meth_, params_);
     }
 
+    virtual void Cancel() {
+      obj_.reset();
+    }
+
    private:
     base::WeakPtr<T> obj_;
     Method meth_;