Remove flaky expectations for SVG text tests that are no longer flaky

BUG=306190
TBR=ojan@chromium.org

Review URL: https://codereview.chromium.org/26468006

git-svn-id: svn://svn.chromium.org/blink/trunk@159782 bbb929c8-8fbe-4397-9dbb-9b2b20218538