Move the shared timer to be dynamically allocated.

content/child/webthread_impl.h

Index: content/child/webthread_impl.h
diff --git a/content/child/webthread_impl.h b/content/child/webthread_impl.h
index 476445284c8938972c4e1fc0558262737a8abb1f..3b5852c032144c1547bcf1deee38264be0454480 100644
--- a/content/child/webthread_impl.h
+++ b/content/child/webthread_impl.h
@@ -64,7 +64,9 @@ class CONTENT_EXPORT WebThreadImpl : public WebThreadBase {
     if (shared_timer_function_)
       shared_timer_function_();
   }
-  base::OneShotTimer<WebThreadImpl> shared_timer_;
+  // The shared timer is a scoped_ptr, so it can be deleted on the same
+  // thread that created it.
+  scoped_ptr<base::OneShotTimer<WebThreadImpl> > shared_timer_;
   SharedTimerFunction shared_timer_function_;
 
   scoped_ptr<base::Thread> thread_;