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

base/trace_event/trace_event_win.cc

Index: base/trace_event/trace_event_win.cc
diff --git a/base/trace_event/trace_event_win.cc b/base/trace_event/trace_event_win.cc
index d2c3dc89e092c2bb83c6031fba82d6f4db0804c9..ebb55c844923daf84b80472cd53a6bffaff7c599 100644
--- a/base/trace_event/trace_event_win.cc
+++ b/base/trace_event/trace_event_win.cc
@@ -9,7 +9,7 @@
 #include <initguid.h>  // NOLINT
 
 namespace base {
-namespace debug {
+namespace trace_event {
 
 using base::win::EtwEventType;
 using base::win::EtwMofEvent;
@@ -120,5 +120,5 @@ void TraceEventETWProvider::Resurrect() {
   StaticMemorySingletonTraits<TraceEventETWProvider>::Resurrect();
 }
 
-}  // namespace debug
+}  // namespace trace_event
 }  // namespace base