Roll external/skia 2f0f5fb37..655ee0f01 (1 commits)

https://skia.googlesource.com/skia.git/+log/2f0f5fb37..655ee0f01

2019-05-30 hcm@google.com Update Skia milestone to 77

The AutoRoll server is located here: https://autoroll-internal.skia.org/r/android-master-autoroll

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, please contact the current sheriff, who should
be CC'd on the roll, and stop the roller if necessary.

Test: Presubmit checks will test this change.
Change-Id: I33cd15b083c9c1eabe30c68f3ba1cbfa9ff94329
Exempt-From-Owner-Approval: The autoroll bot does not require owner approval.