Roll src/third_party/skia/ 698edfece..1a2e3e1e7 (5 commits)

https://skia.googlesource.com/skia.git/+log/698edfecef12..1a2e3e1e77bf

$ git log 698edfece..1a2e3e1e7 --date=short --no-merges --format='%ad %ae %s'
2017-08-03 mtklein Store float and byte constant colors.
2017-08-03 mtklein funnel all constant colors through append_constant_color()
2017-08-03 mtklein Rename append_uniform_color() to append_constant_color().
2017-08-03 mtklein _very_ minor srcover speedup
2017-08-03 mtklein improve HSW 16->8 bit pack

Created with:
  roll-dep src/third_party/skia


Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, see:
http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls


CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
TBR=liyuqian@chromium.org

Change-Id: I2887f4440a4385382c2a5309faf720923a9b54d5
Reviewed-on: https://chromium-review.googlesource.com/600528Reviewed-by: Skia Deps Roller <skia-deps-roller@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491795}

DEPS

@@ -40,7 +40,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and whatever else without interference from each other.
-  'skia_revision': '698edfecef121d8575eee6af207ce8a9525032ee',
+  'skia_revision': '1a2e3e1e77bf7d7da31e8403d88b743f74669c3c',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.