New TimeToFirstURLJob* navigation metrics now work with PlzNavigate.

content/browser/frame_host/navigator.h

Index: content/browser/frame_host/navigator.h
diff --git a/content/browser/frame_host/navigator.h b/content/browser/frame_host/navigator.h
index 191a58366227634b7e51db019cc8cdf6f5453019..ef3c8d2e212f8b9e6257e9054971fc47c8c92be2 100644
--- a/content/browser/frame_host/navigator.h
+++ b/content/browser/frame_host/navigator.h
@@ -140,9 +140,16 @@ class CONTENT_EXPORT Navigator : public base::RefCounted<Navigator> {
 
   // Called when the first resource request for a given navigation is executed
   // so that it can be tracked into an histogram.
+  // PlzNavigate: Called when a navigation is about to make its first potential
+  // network request so that the timestamp can be recorded into an histogram.
+  // TODO(carlosk): once please navigate is the only navigation implementation

[davidben, 2015/01/28 21:33:26]

Nit: please navigate -> PlzNavigate is probably clearer it's referring to the
same thing.

[carlosk, 2015/01/30 14:01:47]

Done. LoL!

+  // remove the URL parameter and rename this method to better suit its naming
+  // conventions.
   virtual void LogResourceRequestTime(
     base::TimeTicks timestamp, const GURL& url) {};
 
+  virtual void LogAboutToBeginNavigation(base::TimeTicks timestamp) {};
+
   // Called to record the time it took to execute the before unload hook for the
   // current navigation.
   virtual void LogBeforeUnloadTime(