Roll src/third_party/skia 5965b73:bb4a1cf

Summary of changes available at:
https://chromium.googlesource.com/skia/+log/5965b73..bb4a1cf

CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
TBR=msarett@google.com

Review URL: https://codereview.chromium.org/1067853004

Cr-Commit-Position: refs/heads/master@{#324100}

DEPS

@@ -42,7 +42,7 @@ vars = {
   'boringssl_git': 'https://boringssl.googlesource.com',
   'libvpx_revision': '861f35b01c87a021540aace739cb7415c08e987b',
   'sfntly_revision': '1bdaae8fc788a5ac8936d68bf24f37d977a13dac',
-  'skia_revision': '5965b73e54da7746e1dafa7c696a4ddf9bd0f271',
+  'skia_revision': 'bb4a1cf0e66c98c723f04f473a3221b2a4d8ece1',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and V8 without interference from each other.