Roll src/third_party/skia 47471cf:d9adfe6

Summary of changes available at:
https://chromium.googlesource.com/skia/+log/47471cf..d9adfe6

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

Review URL: https://codereview.chromium.org/893953002

Cr-Commit-Position: refs/heads/master@{#314111}

DEPS

@@ -42,7 +42,7 @@ vars = {
   'boringssl_git': 'https://boringssl.googlesource.com',
   'libvpx_revision': '5cdd30205301c293be6160f778bce981300b5a28',
   'sfntly_revision': '1bdaae8fc788a5ac8936d68bf24f37d977a13dac',
-  'skia_revision': '47471cf19c1b386212ab0401190ac40cdeb95d1f',
+  'skia_revision': 'd9adfe6a223955bc69c8c7661ab8e0a078afbc32',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.