Rebaseline a couple of svg text tests that are no longer flaky

r159614 fixed a source of font size flakiness, update expectations
accordingly.

TBR=leviw@chromium.org
BUG=webkit.org/b/84854

Review URL: https://codereview.chromium.org/27422002

git-svn-id: svn://svn.chromium.org/blink/trunk@159790 bbb929c8-8fbe-4397-9dbb-9b2b20218538