Findit points to https://chromium-review.googlesource.com/724583 as suspect, assigning to author.

I'll revert and reland

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/eb7dee29e43af9e5b2919ce82bee52fa53b45308

commit eb7dee29e43af9e5b2919ce82bee52fa53b45308
Author: Trent Apted <tapted@chromium.org>
Date: Fri Oct 20 10:22:56 2017

Revert "MacViews: Use the CoreText Harfbuzz shaper."

This reverts commit d19806f0a50d4769e1b208c42312fc2e7b8d5748.

Reason for revert: macOS 10.10 has the RTL bug as well

Bug:  776672 

Original change's description:
> MacViews: Use the CoreText Harfbuzz shaper.
> 
> Currently the OpenType shaper gets used.
> 
> The CoreText shaper gives a closer match to native Cocoa UI, it's what
> the renderer uses on Mac, and it's needed to render Emoji flags
> properly on Mac.
> 
> Bug:  739641 
> Change-Id: I217b1f3be21c571292faac1b0d13c8cc21f2b22f
> Reviewed-on: https://chromium-review.googlesource.com/724583
> Commit-Queue: Trent Apted <tapted@chromium.org>
> Reviewed-by: Michael Wasserman <msw@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#510355}

TBR=msw@chromium.org,tapted@chromium.org

Change-Id: I86a8cfd33769bd12a957fb7343db761e92387c7c
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug:  739641 
Reviewed-on: https://chromium-review.googlesource.com/730523
Reviewed-by: Trent Apted <tapted@chromium.org>
Commit-Queue: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#510395}
[modify] https://crrev.com/eb7dee29e43af9e5b2919ce82bee52fa53b45308/ui/gfx/harfbuzz_font_skia.cc
[modify] https://crrev.com/eb7dee29e43af9e5b2919ce82bee52fa53b45308/ui/gfx/render_text_harfbuzz.cc
[modify] https://crrev.com/eb7dee29e43af9e5b2919ce82bee52fa53b45308/ui/gfx/render_text_unittest.cc

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bc00f85ea66ad1630735d808923aac9858446955

commit bc00f85ea66ad1630735d808923aac9858446955
Author: Trent Apted <tapted@chromium.org>
Date: Fri Oct 20 14:05:11 2017

Reland MacViews: Use the CoreText Harfbuzz shaper.

Currently the OpenType shaper gets used.

The CoreText shaper gives a closer match to native Cocoa UI, it's what
the renderer uses on Mac, and it's needed to render Emoji flags
properly on Mac.

Reviewed in http://crrev.com/c/724583.
Reland extends a workaround for 10.9 to 10.10 as well.

TBR=msw@chromium.org

Bug:  739641 ,  776672 
Change-Id: Ib42b9acd39f97db000af6698b9ea167d374ac889
Reviewed-on: https://chromium-review.googlesource.com/730251
Commit-Queue: Trent Apted <tapted@chromium.org>
Reviewed-by: Trent Apted <tapted@chromium.org>
Cr-Commit-Position: refs/heads/master@{#510425}
[modify] https://crrev.com/bc00f85ea66ad1630735d808923aac9858446955/ui/gfx/harfbuzz_font_skia.cc
[modify] https://crrev.com/bc00f85ea66ad1630735d808923aac9858446955/ui/gfx/render_text_harfbuzz.cc
[modify] https://crrev.com/bc00f85ea66ad1630735d808923aac9858446955/ui/gfx/render_text_unittest.cc