Fix a race in the ChromeFrame metrics service start up code. This race could ...

chrome_frame/metrics_service.h

Index: chrome_frame/metrics_service.h
===================================================================
--- chrome_frame/metrics_service.h	(revision 68089)
+++ chrome_frame/metrics_service.h	(working copy)
@@ -13,6 +13,7 @@
 
 #include "base/basictypes.h"
 #include "base/lazy_instance.h"
+#include "base/lock.h"
 #include "base/metrics/histogram.h"
 #include "base/platform_thread.h"
 #include "base/scoped_ptr.h"
@@ -146,8 +147,10 @@
   // The transmission timer id returned by SetTimer
   int transmission_timer_id_;
 
+  // Used to serialize the Start and Stop operations on the metrics service.
+  static Lock metrics_service_lock_;
+
   DISALLOW_COPY_AND_ASSIGN(MetricsService);
 };
 
 #endif  // CHROME_FRAME_METRICS_METRICS_SERVICE_H_
-