Log operator code histogram on new metric log

chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h

Index: chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h
diff --git a/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h b/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h
index d9ace38066b3510380c436540ef5aa8bab3b3bd6..ccccfd5b63052194913d723c3705b9c79a4b4baf 100644
--- a/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h
+++ b/chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.h
@@ -7,9 +7,11 @@
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
 #include "chrome/browser/chrome_browser_main_extra_parts.h"
 
 class ChromeBrowserMainParts;
+class ChromeBrowserMetricsServiceObserver;
 
 namespace chrome {
 void AddMetricsExtraParts(ChromeBrowserMainParts* main_parts);
@@ -26,6 +28,9 @@ class ChromeBrowserMainExtraPartsMetrics : public ChromeBrowserMainExtraParts {
   virtual void PostBrowserStart() OVERRIDE;
 
  private:
+  // Observe and log histograms on new metric logs.
+  scoped_ptr<ChromeBrowserMetricsServiceObserver> metrics_service_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(ChromeBrowserMainExtraPartsMetrics);
 };