Fix issue 21379

R=danrubel@google.com, paulberry@google.com

Review URL: https://codereview.chromium.org//683673004

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41426 260f80e4-7a28-3924-810f-c04153c831b5
Status page improvements: sort context names, right align numbers, add missing data descriptors.

R=paulberry@google.com

Review URL: https://codereview.chromium.org//685123006

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge@41427 260f80e4-7a28-3924-810f-c04153c831b5