Log operator code histogram on new metric log

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
diff --git a/chrome/browser/chrome_browser_main.cc b/chrome/browser/chrome_browser_main.cc
index d84585d1cdef1629afad49d2ab019c8f900cff10..63b72f004f2858e97fc9282ca327e0822d86d9bd 100644
--- a/chrome/browser/chrome_browser_main.cc
+++ b/chrome/browser/chrome_browser_main.cc
@@ -42,6 +42,7 @@
 #include "chrome/browser/browser_process_platform_part.h"
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/chrome_browser_main_extra_parts.h"
+#include "chrome/browser/chrome_browser_metrics_service_observer.h"
 #include "chrome/browser/component_updater/cld_component_installer.h"
 #include "chrome/browser/component_updater/component_updater_service.h"
 #include "chrome/browser/component_updater/flash_component_installer.h"
@@ -559,9 +560,11 @@ void ChromeBrowserMainParts::SetupMetricsAndFieldTrials() {
   MetricsLog::set_version_extension("-64");
 #endif  // defined(ARCH_CPU_64_BITS)
 
+  MetricsService* metrics = browser_process_->metrics_service();
+  // Create the metrics log observer.
+  metrics_service_observer_.reset(new ChromeBrowserMetricsServiceObserver());
   // Initialize FieldTrialList to support FieldTrials that use one-time
   // randomization.
-  MetricsService* metrics = browser_process_->metrics_service();
   field_trial_list_.reset(
       new base::FieldTrialList(metrics->CreateEntropyProvider().release()));