Add guards to metric values; erase bad events/metrics from db

chrome/browser/ui/webui/performance_monitor/web_ui_handler.cc

Index: chrome/browser/ui/webui/performance_monitor/web_ui_handler.cc
diff --git a/chrome/browser/ui/webui/performance_monitor/web_ui_handler.cc b/chrome/browser/ui/webui/performance_monitor/web_ui_handler.cc
index 16c4085c181f814a700baf196f740c2178367aff..fdc2776e56596a8f9965468d90ac3d6e6e3939de 100644
--- a/chrome/browser/ui/webui/performance_monitor/web_ui_handler.cc
+++ b/chrome/browser/ui/webui/performance_monitor/web_ui_handler.cc
@@ -325,7 +325,8 @@ void DoGetMetric(DictionaryValue* results,
       results,
       metric_type,
       db->GetMaxStatsForActivityAndMetric(metric_type),
-      AggregateMetric(metric_vector.get(),
+      AggregateMetric(metric_type,
+                      metric_vector.get(),
                       start,
                       resolution).get());
 }