Cherry pick HarfBuzz white-space fix
Cherry pick HarfBuzz white-space fix

Cherry pick HarfBuzz change 24f17afeafd40ff77177ed42c9007a0f34fcbb78 for
a right-to-left trailing whitespace issue that is rather serious and can
cause asserts and incorrect behavior on Mac OS. Safe to merge to branch.

R=jchaffraix@chromium.org, behdad@chromium.org
BUG=476913
TEST=fast/text/unicode-fallback-font.html

Review URL: https://codereview.chromium.org/1158783002

Cr-Commit-Position: refs/heads/master@{#331445}
(cherry picked from commit 606c77e1b6c10624bffa4f1cdef74f1e055cd93d)

Review URL: https://codereview.chromium.org/1154763004

Cr-Commit-Position: d34a0005849006230ae7ffb1a9693419810a06bc@{#119}
Cr-Branched-From: 40cda19e609fd36fbf5fe489055423e611631abc@{#330231}

PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,Fireblend/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk,Fireblend/chromium-crosswalk,PeterWangIntel/chromium-crosswalk