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 7f65303ec1ac3f0cff15d79aaf41ca50eb87befc..5c3efc567dbd8a3705878773c6713b1f76520e81 100644
--- a/base/debug/trace_event_impl.h
+++ b/base/debug/trace_event_impl.h
@@ -59,6 +59,7 @@ namespace base {
 
 class WaitableEvent;
 class MessageLoop;
+class SequencedTaskRunner;
 
 namespace debug {
 
@@ -718,7 +719,7 @@ 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_;
 
@@ -729,7 +730,7 @@ 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);