Add option to export tracing events to ETW.

base/trace_event/trace_event_etw_export_win.h

Index: base/trace_event/trace_event_etw_export_win.h
diff --git a/base/trace_event/trace_event_etw_export_win.h b/base/trace_event/trace_event_etw_export_win.h
new file mode 100644
index 0000000000000000000000000000000000000000..73a9d89ccdf84d934845e6456126d14f3ed0e871
--- /dev/null
+++ b/base/trace_event/trace_event_etw_export_win.h
@@ -0,0 +1,66 @@
+// Copyright (c) 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_
+
+#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();
+
+  static void EnableETWExport();
+  static void DisableETWExport();
+
+  static bool isETWExportEnabled() { return GetInstance()->ETWExportEnabled_; }
+
+  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,
+      const unsigned char* arg_types,
+      const unsigned long long* arg_values,
+      const scoped_refptr<ConvertableToTraceFormat>* convertable_values);
+
+  static void AddCustomEvent(const char* name,
+                             char const* phase,
+                             const char* arg_name_1,
+                             const char* arg_value_1,
+                             const char* arg_name_2,
+                             const char* arg_value_2,
+                             const char* arg_name_3,
+                             const char* arg_value_3);
+
+  void Resurrect();
+
+ private:
+  bool ETWExportEnabled_;
+  // 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_