Find latest Chrome OS build with a given Chrome version.

This update allows the user to get test status for the latest Chrome
OS build that contains a given Chrome version. It also stops trying
to retrieve test results flakiness data, which are rarely available
for most Chrome builds, and added little value to this utility.

BUG=chromium:375395
TEST=Put a tests file in the same directory as the script, that lists
the browsertests you want to have a status/results report. Then run:
$ ./browsertest_status.py --tests_file=tests

Change-Id: Ied42921dd9a1b257c05d2015c46aff058c484b37
Reviewed-on: https://chromium-review.googlesource.com/315156
Commit-Ready: Scott Cunningham <scunningham@chromium.org>
Tested-by: Scott Cunningham <scunningham@chromium.org>
Reviewed-by: Scott Cunningham <scunningham@chromium.org>
1 file changed