Roll src/third_party/skia 04ea634:a2ef642

Summary of changes available at:
https://chromium.googlesource.com/skia/+log/04ea634..a2ef642

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

Review URL: https://codereview.chromium.org/845413003

Cr-Commit-Position: refs/heads/master@{#311794}

DEPS

@@ -42,7 +42,7 @@ vars = {
   'boringssl_git': 'https://boringssl.googlesource.com',
   'libvpx_revision': '4f9bd1b106e9e87a02ac2a0d5f9f92a6389b467d',
   'sfntly_revision': '1bdaae8fc788a5ac8936d68bf24f37d977a13dac',
-  'skia_revision': '04ea6344fec074e855c72a43abb399a7088bf38e',
+  'skia_revision': 'a2ef642b00fdd58512b0889d12796d963a27f739',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.