crosperf: remove deprecated tests

Remove the json grammar to parse the result for deprecated tests
dromaeo.*, sunspider and and robohornet_pro. These tests are already
removed from telemetry tests.

BUG=chromium:867332
TEST=none

Change-Id: I06e6e99b51181e30410000223aca1114641cace2
Reviewed-on: https://chromium-review.googlesource.com/1182715


Commit-Ready: Vovo Yang <vovoy@chromium.org>
Tested-by: Vovo Yang <vovoy@chromium.org>
Reviewed-by: Manoj Gupta <manojgupta@chromium.org>