Make WeakPtr use SequenceChecker instead of ThreadChecker

base/thread_task_runner_handle.h

Index: base/thread_task_runner_handle.h
diff --git a/base/thread_task_runner_handle.h b/base/thread_task_runner_handle.h
index 348c071cef27315f2c518a8c8f97c2c43e96c87d..a2935f9aadd0dad2795b2a579ba2682a7cb91d42 100644
--- a/base/thread_task_runner_handle.h
+++ b/base/thread_task_runner_handle.h
@@ -19,7 +19,12 @@ class SingleThreadTaskRunner;
 // constructor.
 class BASE_EXPORT ThreadTaskRunnerHandle {
  public:
-  // Gets the SingleThreadTaskRunner for the current thread.
+  // Gets the SingleThreadTaskRunner for the current thread, or NULL
+  // if one doesn't exist.
+  static scoped_refptr<SingleThreadTaskRunner> GetIfExists();
+
+  // CHECKs that there is a SingleThreadTaskRunner for the current
+  // thread and returns it.
   static scoped_refptr<SingleThreadTaskRunner> Get();

[jar (doing other things), 2013/02/16 02:37:27]

nit: List constructors and destructors before methods on lines 22-28 (even
though it was previously out of order).

 
   explicit ThreadTaskRunnerHandle(