Avoid using ToInternalValue in computing timings, so that the timings are consistent accross platfo…

content/renderer/stats_collection_controller.cc

Index: content/renderer/stats_collection_controller.cc
diff --git a/content/renderer/stats_collection_controller.cc b/content/renderer/stats_collection_controller.cc
index 713407942a7f95b34d8e00cf452882b57a3f1bcc..81c01dda6f482c57027cc0e8b11bef2c61e0cb32 100644
--- a/content/renderer/stats_collection_controller.cc
+++ b/content/renderer/stats_collection_controller.cc
@@ -57,7 +57,8 @@ void ConvertLoadTimeToJSON(
   if (load_start_time.is_null()) {
     item.Set("load_start_ms", base::Value::CreateNullValue());
   } else {
-    item.SetDouble("load_start_ms", load_start_time.ToInternalValue() / 1000);
+    item.SetDouble("load_start_ms", (load_start_time - base::Time::UnixEpoch())
+                   .InMillisecondsF());
   }
   if (load_start_time.is_null() || load_stop_time.is_null()) {
     item.Set("load_duration_ms", base::Value::CreateNullValue());