Roll external/skia be7fc4662..070cbafd6 (5 commits)

https://skia.googlesource.com/skia.git/+log/be7fc4662..070cbafd6

2019-01-04 egdaniel@google.com Add support to gpu command buffers to wrap an external command buffer.
2019-01-04 jcgregorio@google.com Fix link in /dev/contrib.
2019-01-04 michaelludwig@google.com Revert "Use specialized quad lists in rectangle ops"
2019-01-04 brianosman@google.com Add SkColorSpace factory from 3x3 row-major gamut and transfer function
2019-01-04 kjlubick@google.com remove more extra semicolons

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: Iad90fa08d5855943434b4530b56d7bfbb9daa9eb
Exempt-From-Owner-Approval: The autoroll bot does not require owner approval.