Add user_info_ NULL check in case of guest mode.

ash/system/user/tray_user.cc

Index: ash/system/user/tray_user.cc
diff --git a/ash/system/user/tray_user.cc b/ash/system/user/tray_user.cc
index f431980d03a8b6b23ff2342fdd4329d7aff8e58a..c569a7538c606c84d26188f190395836ced20007 100644
--- a/ash/system/user/tray_user.cc
+++ b/ash/system/user/tray_user.cc
@@ -231,10 +231,12 @@ class UserView : public views::View,
           kTrayPopupPaddingHorizontal);
       signout_->SetBoundsRect(signout_bounds);
 
-      gfx::Rect usercard_bounds(user_info_->GetPreferredSize());
-      usercard_bounds.set_width(signout_bounds.x());
-      user_info_->SetBoundsRect(usercard_bounds);
-    } else {
+      if (user_info_) {
+        gfx::Rect usercard_bounds(user_info_->GetPreferredSize());
+        usercard_bounds.set_width(signout_bounds.x());
+        user_info_->SetBoundsRect(usercard_bounds);
+      }

[sadrul, 2012/05/17 17:07:32]

I think what this will do is we will end up with empty space on the left, and an
exit button on the right. I think instead, the button should expand to fill up
the whole row.

[Jun Mukai, 2012/05/17 20:13:36]

Done.

+    } else if (user_info_) {
       user_info_->SetBoundsRect(gfx::Rect(size()));
     }
   }