User interruption should still create results.html for run-webkit-tests.

Currently, results.html is generated from the results json file only on
completion of entire layout tests run. Ideally, it should be created even
when the execution has been interrupted - either by user or because of
any interruption. In both cases, all failures should be reported.

BUG=263151

Review URL: https://chromiumcodereview.appspot.com/23496003

git-svn-id: svn://svn.chromium.org/blink/trunk@157769 bbb929c8-8fbe-4397-9dbb-9b2b20218538