Replace "nested message loop" with "nested run loop" in comments.

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 <utility>
 
 #include "base/bind.h"
@@ skipping 400 matching lines @@
 }
 
 bool MessageLoop::DeferOrRunPendingTask(PendingTask pending_task) {
   if (pending_task.nestable || !is_nested_) {
     RunTask(&pending_task);
     // Show that we ran a task (Note: a new one might arrive as a
     // consequence!).
     return true;
   }
 
-  // We couldn't run the task now because we're in a nested message loop
+  // We couldn't run the task now because we're in a nested run loop
   // and the task isn't nestable.
   deferred_non_nestable_work_queue_.push(std::move(pending_task));
   return false;
 }
 
 void MessageLoop::AddToDelayedWorkQueue(PendingTask pending_task) {
   // Move to the delayed work queue.
   delayed_work_queue_.push(std::move(pending_task));
 }
 
@@ skipping 210 matching lines @@
       persistent,
       mode,
       controller,
       delegate);
 }
 #endif
 
 #endif  // !defined(OS_NACL_SFI)
 
 }  // namespace base