Move Singleton and related structs to namespace base

base/trace_event/trace_log.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_TRACE_EVENT_TRACE_LOG_H_
 #define BASE_TRACE_EVENT_TRACE_LOG_H_
 
 #include "base/trace_event/memory_dump_provider.h"
 #include "base/trace_event/trace_config.h"
 #include "base/trace_event/trace_event_impl.h"
 
 // Older style trace macros with explicit id and extra data
 // Only these macros result in publishing data to ETW as currently implemented.
 // TODO(georgesak): Update/replace these with new ETW macros.
 #define TRACE_EVENT_BEGIN_ETW(name, id, extra)   \
   base::trace_event::TraceLog::AddTraceEventEtw( \
       TRACE_EVENT_PHASE_BEGIN, name, reinterpret_cast<const void*>(id), extra)
 
 #define TRACE_EVENT_END_ETW(name, id, extra)     \
   base::trace_event::TraceLog::AddTraceEventEtw( \
       TRACE_EVENT_PHASE_END, name, reinterpret_cast<const void*>(id), extra)
 
 #define TRACE_EVENT_INSTANT_ETW(name, id, extra)                          \
   base::trace_event::TraceLog::AddTraceEventEtw(                          \
       TRACE_EVENT_PHASE_INSTANT, name, reinterpret_cast<const void*>(id), \
       extra)
 
+namespace base {
+
 template <typename Type>
 struct DefaultSingletonTraits;
-
-namespace base {
-
 class RefCountedString;
 
 namespace trace_event {
 
 class TraceBuffer;
 class TraceBufferChunk;
 class TraceEvent;
 class TraceEventMemoryOverhead;
 class TraceSamplingThread;
 
@@ skipping 442 matching lines @@
   subtle::AtomicWord generation_;
   bool use_worker_thread_;
 
   DISALLOW_COPY_AND_ASSIGN(TraceLog);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
 #endif  // BASE_TRACE_EVENT_TRACE_LOG_H_