Updates to test list API doc.

Added new sections "Adding a new test list" and "Converting old-style
test lists".

BUG=None
TEST=None

Change-Id: I0f5de5302832762da8b801df9ed8f5637a4ceb16
Reviewed-on: https://chromium-review.googlesource.com/179427
Reviewed-by: Jon Salz <jsalz@chromium.org>
Commit-Queue: Jon Salz <jsalz@chromium.org>
Tested-by: Jon Salz <jsalz@chromium.org>
1 file changed