Roll src/third_party/skia 37dd331:a6ca5a0

Summary of changes available at:
https://chromium.googlesource.com/skia/+log/37dd331..a6ca5a0

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

Review URL: https://codereview.chromium.org/701593003

Cr-Commit-Position: refs/heads/master@{#302534}

DEPS

@@ -44,7 +44,7 @@ vars = {
   'boringssl_git': 'https://boringssl.googlesource.com',
   'libvpx_revision': '2e5ced5fd62a73f4f5687ab19520b3aad1c53f6f',
   'sfntly_revision': '1bdaae8fc788a5ac8936d68bf24f37d977a13dac',
-  'skia_revision': '37dd331b20a92ce79cc26556e065dec98a66cb0b',
+  'skia_revision': 'a6ca5a002ee62a1a6b146111cd9bc3f0c4891122',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.