Roll src/third_party/skia/ f93d71122..1bd72ba2c (4 commits).

https://chromium.googlesource.com/skia.git/+log/f93d71122e4f..1bd72ba2cb34

$ git log f93d71122..1bd72ba2c --date=short --no-merges --format='%ad %ae %s'
2016-09-16 mtklein GN: add a flag to implement Android_FrameworkDefs bot.
2016-09-16 bungeman Make Sk2DPathEffect thread safe.
2016-09-16 mtklein Update GN docs to mention is_official_build and ndk_api.
2016-09-16 mtklein GN: enable Vulkan on Android when API >= 24.

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

Review-Url: https://codereview.chromium.org/2347123003
Cr-Commit-Position: refs/heads/master@{#419175}

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': 'f93d71122e4fcfcdc674a0163455990b13855f2f',
+  'skia_revision': '1bd72ba2cb349788223e3e7304f25751c87f1f95',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.