Replace base::Callback with base::OnceCallback in base::PendingTask

base/bind.h

Index: base/bind.h
diff --git a/base/bind.h b/base/bind.h
index ec707a0618f288431e373ffe56b3813c409754a3..b4037351966bfc56320fcba45e67b5f1b5203cb5 100644
--- a/base/bind.h
+++ b/base/bind.h
@@ -81,6 +81,11 @@ Bind(Functor&& functor, Args&&... args) {
                                  std::forward<Args>(args)...);
 }
 
+// Converts a OnceClosure to a RepeatingClosure. It hits CHECK failure to run
+// the resulting RepeatingClosure more than once.
+BASE_EXPORT internal::RepeatingClosure UnsafeConvertOnceClosureToRepeating(

[fdoray, 2016/10/06 17:37:22]

Do you plan to use OnceClosure instead of Closure in TaskRunner? I would be in
favor of that change.

If so, add a TODO to remove this function once TaskRunner uses OnceClosure
(third_party/WebKit/Source/platform/scheduler/base/task_queue_manager.cc will no
longer need this conversion)

[tzik, 2016/10/13 05:58:04]

Yes, here is a CL to do that, though it's a bit stale now.
https://codereview.chromium.org/2122543002/
Done.

+    internal::OnceClosure cb);
+
 }  // namespace base
 
 #endif  // BASE_BIND_H_