Mark acid3-test-77 as passing.

svg/custom/acid3-test-77.html has been passing for some time and is no
longer flaky or slow [1]. This patch marks the test as passing on all
platforms.

[1] http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=svg%2Fcustom%2Facid3-test-77.html

TBR=falken
BUG=311487

Review URL: https://codereview.chromium.org/364683002

git-svn-id: svn://svn.chromium.org/blink/trunk@177330 bbb929c8-8fbe-4397-9dbb-9b2b20218538