Kick the pump when allowing nestable tasks on a message loop

base/message_loop/message_loop.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/message_loop/message_loop.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
@@ skipping 340 matching lines @@
 static void QuitCurrentWhenIdle() {
   MessageLoop::current()->QuitWhenIdle();
 }
 
 // static
 Closure MessageLoop::QuitWhenIdleClosure() {
   return Bind(&QuitCurrentWhenIdle);
 }
 
 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 {
   return nestable_tasks_allowed_;
 }
 
 bool MessageLoop::IsNested() {
   return run_loop_->run_depth_ > 1;
 }
 
@@ skipping 405 matching lines @@
       fd,
       persistent,
       mode,
       controller,
       delegate);
 }
 
 #endif
 
 }  // namespace base