Update from https://crrev.com/307330

Includes several sky updates for skia API changes and the gn format
presubmit check from https://codereview.chromium.org/779193003/

Review URL: https://codereview.chromium.org/786123002
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 47ccdc7..ce66452 100644
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -1542,6 +1542,8 @@
   results.extend(_CommonChecks(input_api, output_api))
   results.extend(_CheckValidHostsInDEPS(input_api, output_api))
   results.extend(_CheckJavaStyle(input_api, output_api))
+  results.extend(
+      input_api.canned_checks.CheckGNFormatted(input_api, output_api))
   return results