Revert "Revert "Improve quad edges' smoothness in non-AA cases""

This reverts commit 1e74cad9b4ed8079433d4e62ab3198d97436f5ec.

Reason for revert: the guard flag has now been confirmed to be landed on chromium/src. We should now be able to pass the layout tests.

Original change's description:
> Revert "Improve quad edges' smoothness in non-AA cases"
> 
> This reverts commit d4ed326d6f3704995b0e91292bf2c87e9d36bb14.
> 
> Reason for revert: reverting temporarily to get us rolling into Chrome again.
> 
> Must be this CL right?
> https://storage.googleapis.com/chromium-layout-test-archives/linux_trusty_blink_rel/3364/layout-test-results/results.html
> 
> Original change's description:
> > Improve quad edges' smoothness in non-AA cases
> > 
> > Previously, non-AA quad edges only have an accuracy about 1/2 pixel
> > (while the AA quad edges have an accuracy about 1/8 pixel).  Now, we
> > increase non-AA quad edges' accuracy to 1/8 pixel as well.
> > 
> > The difference is very significant for rotating non-AA filled circles.
> > For example, run `./out/Debug/SampleApp --slide GM:fillcircle` with AA
> > turned off (by pressing b).
> > 
> > The benchmark added reveals that increasing quad accuracy from 1/2 to
> > 1/8 doesn't affect the performance significantly. The following is the
> > 1/2-accuracy performance versus 1/8-accuracy performance:
> > 
> > curr/maxrss     loops   min     median  mean    max     stddev  samples
> > config  bench
> > 7/17  MB        19      2.43µs  2.57µs  2.81µs  10.5µs  22%     16119
> > 8888    path_fill_big_nonaacircle
> > 7/17  MB        17      1.38µs  1.42µs  1.52µs  13µs    20%     21409
> > 8888    path_fill_small_nonaacircle
> > 
> > curr/maxrss     loops   min     median  mean    max     stddev  samples
> > config  bench
> > 7/17  MB        71      2.52µs  2.59µs  2.79µs  7.67µs  19%     7557
> > 8888    path_fill_big_nonaacircle
> > 7/17  MB        64      1.45µs  1.49µs  1.51µs  2.39µs  5%      12704
> > 8888    path_fill_small_nonaacircle
> > 
> > 
> > BUG=skia:
> > 
> > Change-Id: I3482098aeafcc6f2ec9aa3382977c0dc1b650964
> > Reviewed-on: https://skia-review.googlesource.com/6699
> > Reviewed-by: Mike Reed <reed@google.com>
> > Commit-Queue: Yuqian Li <liyuqian@google.com>
> > 
> 
> TBR=caryclark@google.com,liyuqian@google.com,reed@google.com,djsollen@google.com,bungeman@google.com,reviews@skia.org,fmalita@chromium.org
> BUG=skia:
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> 
> Change-Id: I5bc4596ab506f6f61ac2da91a07cf51d61114f31
> Reviewed-on: https://skia-review.googlesource.com/6829
> Commit-Queue: Mike Klein <mtklein@google.com>
> Reviewed-by: Mike Klein <mtklein@google.com>
> 

TBR=djsollen@google.com,mtklein@google.com,bungeman@google.com,reviews@skia.org,caryclark@google.com,fmalita@chromium.org,liyuqian@google.com,reed@google.com
BUG=skia:
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Change-Id: I0ec2ea8dc0c6ad0ebdcb48878fb301c32443a09e
Reviewed-on: https://skia-review.googlesource.com/6858
Commit-Queue: Yuqian Li <liyuqian@google.com>
Reviewed-by: Yuqian Li <liyuqian@google.com>
2 files changed