Roll src/third_party/skia 96a6c4d:4de8a4d

Summary of changes available at:
https://chromium.googlesource.com/skia/+log/96a6c4d..4de8a4d

CQ_EXTRA_TRYBOTS=tryserver.blink:linux_blink_rel,linux_blink_dbg
TBR=halcanary@google.com

Review URL: https://codereview.chromium.org/771853003

Cr-Commit-Position: refs/heads/master@{#306711}

DEPS

@@ -44,7 +44,7 @@ vars = {
   'boringssl_git': 'https://boringssl.googlesource.com',
   'libvpx_revision': '64bec311643752b040741ef8b2d293e75c31218a',
   'sfntly_revision': '1bdaae8fc788a5ac8936d68bf24f37d977a13dac',
-  'skia_revision': '96a6c4df417a2382dd183b0dbc1c614819795f2a',
+  'skia_revision': '4de8a4dcf70fdaef7ff4e875e6f7c018053491d7',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.