Rebaseline virtual/prefer_compositing_to_lcd_text/compositing/overflow/updating-scrolling-content.html on mac

Some one changed code affecting the result after the bots generated
results and before auto-rebaseline script rebaselined the test using
the results from the bot.

BUG=416535
TBR=morrita@chromium.org

Review URL: https://codereview.chromium.org/696523004

git-svn-id: svn://svn.chromium.org/blink/trunk@184678 bbb929c8-8fbe-4397-9dbb-9b2b20218538