Move kInstallDate from chrome/common/pref_names.h to components/metrics/metrics_pref_names.h

components/metrics/metrics_log.h

Index: components/metrics/metrics_log.h
diff --git a/components/metrics/metrics_log.h b/components/metrics/metrics_log.h
index 8da307849651f81e01c836ea74c2b7fca9bebc55..2d0519e9381bb5511e8aac33e7414351a0a6424b 100644
--- a/components/metrics/metrics_log.h
+++ b/components/metrics/metrics_log.h
@@ -96,7 +96,8 @@ class MetricsLog {
   // is determined by the pref value.
   void RecordEnvironment(
       const std::vector<metrics::MetricsProvider*>& metrics_providers,
-      const std::vector<variations::ActiveGroupId>& synthetic_trials);
+      const std::vector<variations::ActiveGroupId>& synthetic_trials,
+      int64 install_date);
 
   // Loads the environment proto that was saved by the last RecordEnvironment()
   // call from prefs and clears the pref value. Returns true on success or false