[cros] OOBE: add histograms for Profile image fetching.

chrome/browser/chromeos/login/user_image_screen.h

Index: chrome/browser/chromeos/login/user_image_screen.h
diff --git a/chrome/browser/chromeos/login/user_image_screen.h b/chrome/browser/chromeos/login/user_image_screen.h
index 06b0ab31d4736b2fadff720d5c955b20a42f2383..67159c9643a7e43bc4996ba6785d7505256e397f 100644
--- a/chrome/browser/chromeos/login/user_image_screen.h
+++ b/chrome/browser/chromeos/login/user_image_screen.h
@@ -7,6 +7,7 @@
 #pragma once
 
 #include "base/memory/scoped_ptr.h"
+#include "base/time.h"
 #include "chrome/browser/chromeos/login/camera_controller.h"
 #include "chrome/browser/chromeos/login/profile_image_downloader.h"
 #include "chrome/browser/chromeos/login/user_image_screen_actor.h"
@@ -64,6 +65,9 @@ class UserImageScreen: public WizardScreen,
 
   scoped_ptr<ProfileImageDownloader> profile_image_downloader_;
 
+  // Time when the profile image download has started.
+  base::Time profile_image_load_start_time_;
+
   DISALLOW_COPY_AND_ASSIGN(UserImageScreen);
 };