Add LookaheadFilterInterpreter code coverage

BUG=b:286851905
TEST=USE="coverage" FEATURES="test noclean" emerge-brya chromeos-base/gesture

Change-Id: I8a4daeb48be471f565bab8bf963da629075c1289
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/gestures/+/4874991
Tested-by: Denis Brockus <dbrockus@chromium.org>
Reviewed-by: Harry Cutts <hcutts@chromium.org>
Commit-Queue: Denis Brockus <dbrockus@chromium.org>
Code-Coverage: Zoss <zoss-cl-coverage@prod.google.com>
2 files changed