Move Singleton and related structs to namespace base

base/trace_event/trace_log.cc

Index: base/trace_event/trace_log.cc
diff --git a/base/trace_event/trace_log.cc b/base/trace_event/trace_log.cc
index af2124efd007c1f17b7279190ec7482244ebc869..f0f060748d064c664337d40e4d76b7f38aa16873 100644
--- a/base/trace_event/trace_log.cc
+++ b/base/trace_event/trace_log.cc
@@ -39,18 +39,20 @@
 #include "base/trace_event/trace_event_win.h"
 #endif
 
+// The thread buckets for the sampling profiler.
+BASE_EXPORT TRACE_EVENT_API_ATOMIC_WORD g_trace_state[3];
+
+namespace base {
+
 class DeleteTraceLogForTesting {
  public:
   static void Delete() {
-    Singleton<base::trace_event::TraceLog,
-              LeakySingletonTraits<base::trace_event::TraceLog>>::OnExit(0);
+    base::Singleton<
+        trace_event::TraceLog,
+        LeakySingletonTraits<base::trace_event::TraceLog>>::OnExit(0);
   }
 };
 
-// The thread buckets for the sampling profiler.
-BASE_EXPORT TRACE_EVENT_API_ATOMIC_WORD g_trace_state[3];
-
-namespace base {
 namespace trace_event {
 
 namespace {