Convert NavigationMetricsRecorder to use the new navigation callbacks.

chrome/browser/tab_contents/navigation_metrics_recorder.h

Index: chrome/browser/tab_contents/navigation_metrics_recorder.h
diff --git a/chrome/browser/tab_contents/navigation_metrics_recorder.h b/chrome/browser/tab_contents/navigation_metrics_recorder.h
index a13bba98c02da6efa9d947918eb85eaaad965af2..4dc18c84d2dbe7026ca1462f4f0ef6ad4602306b 100644
--- a/chrome/browser/tab_contents/navigation_metrics_recorder.h
+++ b/chrome/browser/tab_contents/navigation_metrics_recorder.h
@@ -38,9 +38,8 @@ class NavigationMetricsRecorder
   friend class content::WebContentsUserData<NavigationMetricsRecorder>;
 
   // content::WebContentsObserver overrides:
-  void DidNavigateMainFrame(
-      const content::LoadCommittedDetails& details,
-      const content::FrameNavigateParams& params) override;
+  void DidFinishNavigation(
+      content::NavigationHandle* navigation_handle) override;
 
   rappor::RapporServiceImpl* rappor_service_;