Revert &quotOptimize complex text shaping&quot

      This reverts r191227, commit 5e98373a2a52b76edbb143cdf42f6d489ceedde1 as
it caused a glyph fallback regression on a number of high profile pages.


TBR=leviw@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/985213002

git-svn-id: svn://svn.chromium.org/blink/trunk@191572 bbb929c8-8fbe-4397-9dbb-9b2b20218538