Roll src/third_party/skia f6f8050:dfb7da3

Summary of changes available at:
https://chromium.googlesource.com/skia/+log/f6f8050..dfb7da3

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

Review URL: https://codereview.chromium.org/925123002

Cr-Commit-Position: refs/heads/master@{#316406}

DEPS

@@ -42,7 +42,7 @@ vars = {
   'boringssl_git': 'https://boringssl.googlesource.com',
   'libvpx_revision': '5cdd30205301c293be6160f778bce981300b5a28',
   'sfntly_revision': '1bdaae8fc788a5ac8936d68bf24f37d977a13dac',
-  'skia_revision': 'f6f8050837c3236b8c3aa4cbd83625ed831f4cd0',
+  'skia_revision': 'dfb7da35642368718ba7ac18216511bdfd496a19',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.