Update from https://crrev.com/329939

base/trace_event/trace_event_etw_export_win.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.
 
 // This file contains the Windows-specific exporting to ETW.
-#ifndef BASE_TRACE_EVENT_TRACE_ETW_EXPORT_H_
-#define BASE_TRACE_EVENT_TRACE_ETW_EXPORT_H_
+#ifndef BASE_TRACE_EVENT_TRACE_EVENT_ETW_EXPORT_WIN_H_
+#define BASE_TRACE_EVENT_TRACE_EVENT_ETW_EXPORT_WIN_H_
 
 #include "base/base_export.h"
 #include "base/trace_event/trace_event_impl.h"
 
 // Fwd.
 template <typename Type>
 struct StaticMemorySingletonTraits;
 
 namespace base {
 namespace trace_event {
 
 class BASE_EXPORT TraceEventETWExport {
  public:
   ~TraceEventETWExport();
 
   // Retrieves the singleton.
   // Note that this may return NULL post-AtExit processing.
   static TraceEventETWExport* GetInstance();
 
   // Enables/disables exporting of events to ETW. If disabled,
   // AddEvent and AddCustomEvent will simply return when called.
   static void EnableETWExport();
   static void DisableETWExport();
 
-  static bool isETWExportEnabled() { return GetInstance()->ETWExportEnabled_; }
+  static bool isETWExportEnabled() {
+    return (GetInstance() && GetInstance()->ETWExportEnabled_);
+  }
 
   // Exports an event to ETW. This is mainly used in
   // TraceLog::AddTraceEventWithThreadIdAndTimestamp to export internal events.
   static void AddEvent(
       char phase,
       const unsigned char* category_group_enabled,
       const char* name,
       unsigned long long id,
       int num_args,
       const char** arg_names,
@@ skipping 20 matching lines @@
   // Ensure only the provider can construct us.
   friend struct StaticMemorySingletonTraits<TraceEventETWExport>;
   TraceEventETWExport();
 
   DISALLOW_COPY_AND_ASSIGN(TraceEventETWExport);
 };
 
 }  // namespace trace_event
 }  // namespace base
 
-#endif  // BASE_TRACE_EVENT_TRACE_ETW_EXPORT_H_
+#endif  // BASE_TRACE_EVENT_TRACE_EVENT_ETW_EXPORT_WIN_H_