[cros] User image selection wraps when navigating with arrow keys.

BUG=chromium-os:19010
TEST=Manual: open user image selection dialog, move to the last image and press the right arrow.


Review URL: http://codereview.chromium.org/7784003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@98680 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/chromeos/login/oobe_screen_user_image.js

@@ -125,13 +125,10 @@ cr.define('oobe', function() {
     userImageList.addEventListener('keydown', function(e) {
       var prevIndex = userImageScreen.selectedUserImage_;
       var len = userImageList.children.length;
-      if (e.keyCode == 39 || e.keyCode == 40) {  // right or down
-        if (prevIndex < len - 1)
-          UserImageScreen.selectUserImage(prevIndex + 1);
-      } else if (e.keyCode == 37 || e.keyCode == 38) {  // left or up
-        if (prevIndex > 0)
-          UserImageScreen.selectUserImage(prevIndex - 1);
-      }
+      if (e.keyCode == 39 || e.keyCode == 40)  // right or down
+        UserImageScreen.selectUserImage((prevIndex + 1) % len);
+      else if (e.keyCode == 37 || e.keyCode == 38)  // left or up
+        UserImageScreen.selectUserImage((prevIndex - 1 + len) % len);
       e.stopPropagation();
     });
   };