Roll external/skia a377184a5..288d041c6 (7 commits)
https://skia.googlesource.com/skia.git/+log/a377184a5..288d041c6
2017-05-05 csmartdalton@google.com GL: track enabled vertex arrays as a count rather than a mask
2017-05-05 ethannicholas@google.com sksl optimizer fixes
2017-05-05 reed@google.com optimize gaussian with herbs quartic
2017-05-05 halcanary@google.com header cleanup
2017-05-05 halcanary@google.com Revert "Revert "SkTypeface::getAdvancedMetrics(): cleanup""
2017-05-05 mtklein@chromium.org add -Wno-error=attributes for G3 Android builds
2017-05-05 fmalita@chromium.org Local matrix support for RP gradients
Test: Presubmit checks will test this change.
Change-Id: I6f0662fece1394068575035639f18c636c366e46