Move tracing namespace from base::debug to base::trace_event.

content/renderer/scheduler/renderer_scheduler_impl.h

Index: content/renderer/scheduler/renderer_scheduler_impl.h
diff --git a/content/renderer/scheduler/renderer_scheduler_impl.h b/content/renderer/scheduler/renderer_scheduler_impl.h
index ccf5881c4c0ca2bdd645125ee47525dd889414a6..0c41e501e04fc026af1f49d0b7c35e5ce20f3120 100644
--- a/content/renderer/scheduler/renderer_scheduler_impl.h
+++ b/content/renderer/scheduler/renderer_scheduler_impl.h
@@ -14,9 +14,12 @@
 #include "content/renderer/scheduler/task_queue_manager.h"
 
 namespace base {
-namespace debug {
+namespace trace_event {
 class ConvertableToTraceFormat;
 }
+namespace debug {
+using ::base::trace_event::ConvertableToTraceFormat;
+}
 }
 
 namespace content {