Roll src/third_party/skia 6a4e60bb8f49..642c7b758944 (3 commits)

https://skia.googlesource.com/skia.git/+log/6a4e60bb8f49..642c7b758944


git log 6a4e60bb8f49..642c7b758944 --date=short --no-merges --format='%ad %ae %s'
2018-07-24 recipe-roller@chromium.org Roll recipe dependencies (trivial).
2018-07-24 ethannicholas@google.com fixed geometry shaders when canUseFragCoord is false
2018-07-24 caryclark@skia.org handle failing pathop tests


Created with:
  gclient setdep -r src/third_party/skia@642c7b758944

The AutoRoll server is located here: https://autoroll.skia.org

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

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel;luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel

BUG=chromium:859705
TBR=benjaminwagner@chromium.org

Change-Id: Id2d15a495b85a2c515b0c84b3ca1cd2993fff570
Reviewed-on: https://chromium-review.googlesource.com/1147915Reviewed-by: skia-chromium-autoroll <skia-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Commit-Queue: skia-chromium-autoroll <skia-chromium-autoroll@skia-buildbots.google.com.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/master@{#577674}

DEPS

@@ -105,7 +105,7 @@ 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': '6a4e60bb8f49e4a031e8fc99c4d8edaa25b3619f',
+  'skia_revision': '642c7b758944b0b35aa5f19ed8a034b621493b43',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.