Sort waterfall rows by start time, not resourceId

Instead of listing the waterfall rows by resourceId, sort them by the first 
timestamp per row (i.e. DNS Lookup if present, else Initial Connection if 
present, else Time to First Byte).

Keep the data exactly as-is -- don't renumber the resourceIds! -- just reorder 
the rows.

Ditto for the Connection View rows.

If you want to generalize this, we could add radio buttons (or, better, legend 
links) to allow sorting by:
   - resourceId
   - DNS Lookup (the default)
   - Initial Connection  (== DNS Lookup end)
   - Time to First Byte  (== Initial Connection end)
   - Content Download (== Time to First Byte end)
   - Finished Load (== Content Download end)
This'd make it easy to (e.g.) sort by when each resource had finished loading, 
as opposed to started loading.

Original issue reported on code.google.com by z...@google.com on 20 May 2013 at 6:54

acmh / webpagetest

Sort waterfall rows by start time, not resourceId #158