Roll src/third_party/skia/ 308b5ac68..bd72f5a05 (1 commit).

https://skia.googlesource.com/skia.git/+log/308b5ac681d5..bd72f5a05c43

$ git log 308b5ac68..bd72f5a05 --date=short --no-merges --format='%ad %ae %s'
2016-12-06 bsalomon Tighten up when a line requires aa in SkGpuDevice.

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
TBR=herb@google.com

Review-Url: https://codereview.chromium.org/2558813002
Cr-Commit-Position: refs/heads/master@{#436970}

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': '308b5ac681d5423ddafd208e3d90179e6dc9502e',
+  'skia_revision': 'bd72f5a05c430e697e1eca24e5327d3a5755b8ae',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.