DO NOT SUBMIT. Hacky trace event data for MessagePumpMac.

base/message_loop/message_loop.cc

Index: base/message_loop/message_loop.cc
diff --git a/base/message_loop/message_loop.cc b/base/message_loop/message_loop.cc
index d2eafbd8489fd32c0822ebe9b740c2f560f1c3a2..cf62893f3656e5a28d96dc1cb9181fc7a8f7aabb 100644
--- a/base/message_loop/message_loop.cc
+++ b/base/message_loop/message_loop.cc
@@ -457,6 +457,10 @@ void MessageLoop::RunTask(const PendingTask& pending_task) {
   TRACE_EVENT2("task", "MessageLoop::RunTask",
                "src_file", pending_task.posted_from.file_name(),
                "src_func", pending_task.posted_from.function_name());
+  TRACE_EVENT2("task", "MessageLoop::PostTask",
+               "queue_size", work_queue_.size() + 1,  // +1 for this task.
+               "queueing_delay", (start_time -
+                   pending_task.EffectiveTimePosted()).InMilliseconds());
 
   DCHECK(nestable_tasks_allowed_);
   // Execute the task and assume the worst: It is probably not reentrant.