v1 UI had the ability to add all subtests for a given test. We should add back that ability to v2 UI.
Created attachment 254945 [details] Adds the feature
Created attachment 254946 [details] Alternative pane button screenshot
Comment on attachment 254945 [details] Adds the feature rs=me
Committed r185594: <http://trac.webkit.org/changeset/185594>