Kick the pump when allowing nestable tasks on a message loop

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 e03572675aa8528a04034463e9c25cb35b2a98f7..3f9d01c8620f9de69d734783e8b340661cd019ea 100644
--- a/base/message_loop/message_loop.cc
+++ b/base/message_loop/message_loop.cc
@@ -358,13 +358,12 @@ Closure MessageLoop::QuitWhenIdleClosure() {
 }
 
 void MessageLoop::SetNestableTasksAllowed(bool allowed) {
-  if (nestable_tasks_allowed_ != allowed) {
-    nestable_tasks_allowed_ = allowed;
-    if (!nestable_tasks_allowed_)
-      return;
-    // Start the native pump if we are not already pumping.
+  if (allowed) {
+    // Kick the native pump just in case we enter a OS-driven nested message
+    // loop.
     pump_->ScheduleWork();
   }
+  nestable_tasks_allowed_ = allowed;
 }
 
 bool MessageLoop::NestableTasksAllowed() const {