Add option to export tracing events to ETW.

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 69d0941ea98aa3d3b59d69990e50d468da97f344..5aa4dd82b23566ba61cab40f07e1f9129070fe17 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -975,6 +975,10 @@ const char kEnableWin32kRendererLockDown[] =
 // This switch allows specifying suffix to shared memory section name to avoid
 // clashes between different instances of Chrome.
 const char kFontCacheSharedMemSuffix[] = "font-cache-shared-mem-suffix";
+
+// Enables the exporting of the tracing events to ETW. This is only supported on
+// Windows Vista and later.
+const char kTraceExportEventsToETW[] = "trace-export-events-to-etw";
 #endif
 
 // Enables the use of NPAPI plugins.