Roll src/third_party/skia/ 122fac306..927ac9c53 (4 commits).

https://chromium.googlesource.com/skia.git/+log/122fac306189..927ac9c53208

$ git log 122fac306..927ac9c53 --date=short --no-merges --format='%ad %ae %s'
2016-09-19 egdaniel Refactor vulkan buffer mapping and unmapping
2016-09-19 bsalomon Revert of Stop flattening GrCoordTransforms in parent GrFragmentProcessors. (patchset #3 id:40001 of https://codereview.chromium.org/2339203002/ )
2016-09-19 mtklein To prep for removing CMake bots, take them off the CQ and presubmit.
2016-09-19 bsalomon Stop flattening GrCoordTransforms in parent GrFragmentProcessors.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_precise_blink_rel
TBR=borenet@google.com

Review-Url: https://codereview.chromium.org/2348183004
Cr-Commit-Position: refs/heads/master@{#419494}

DEPS

@@ -36,7 +36,7 @@ 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': '122fac306189940a4135e884eaef71a9aa0d5c8a',
+  'skia_revision': '927ac9c532084c816801434340383e4bd822c726',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.