Reduce usage of MessageLoopProxy in base/

base/debug/trace_event_impl.h

Index: base/debug/trace_event_impl.h
diff --git a/base/debug/trace_event_impl.h b/base/debug/trace_event_impl.h
index bac74e3f39f6bd0e512a142c1f876c2a7d9849af..b55964c35118b5694e4234693f38fc17c2b9b886 100644
--- a/base/debug/trace_event_impl.h
+++ b/base/debug/trace_event_impl.h
@@ -49,6 +49,7 @@ namespace base {
 
 class WaitableEvent;
 class MessageLoop;
+class SequencedTaskRunner;
 
 namespace debug {
 
@@ -787,7 +788,7 @@ class BASE_EXPORT TraceLog {
   ThreadLocalBoolean thread_is_in_trace_event_;
 
   // Contains the message loops of threads that have had at least one event
-  // added into the local event buffer. Not using MessageLoopProxy because we
+  // added into the local event buffer. Not using TaskRunners because we
   // need to know the life time of the message loops.
   hash_set<MessageLoop*> thread_message_loops_;
 
@@ -798,7 +799,7 @@ class BASE_EXPORT TraceLog {
 
   // Set when asynchronous Flush is in progress.
   OutputCallback flush_output_callback_;
-  scoped_refptr<MessageLoopProxy> flush_message_loop_proxy_;
+  scoped_refptr<SequencedTaskRunner> flush_task_runner_;
   subtle::AtomicWord generation_;
 
   DISALLOW_COPY_AND_ASSIGN(TraceLog);