Added UMA metrics for ChromeOS first-run UI.

chrome/browser/chromeos/first_run/first_run_controller.h

Index: chrome/browser/chromeos/first_run/first_run_controller.h
diff --git a/chrome/browser/chromeos/first_run/first_run_controller.h b/chrome/browser/chromeos/first_run/first_run_controller.h
index 85f3eb67b9e17737cde8546eadc7b239b746c32f..86ea1a1a45e77bf7051c77556a2ad162f560da6f 100644
--- a/chrome/browser/chromeos/first_run/first_run_controller.h
+++ b/chrome/browser/chromeos/first_run/first_run_controller.h
@@ -14,6 +14,7 @@
 #include "base/compiler_specific.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/time/time.h"
 #include "chrome/browser/ui/webui/chromeos/first_run/first_run_actor.h"
 
 class Profile;
@@ -94,6 +95,9 @@ class FirstRunController : public FirstRunActor::Delegate,
   // Web contents of WebUI.
   content::WebContents* web_contents_for_tests_;
 
+  // Time when tutorial was started.
+  base::Time start_time_;
+
   DISALLOW_COPY_AND_ASSIGN(FirstRunController);
 };