Roll external/skia 50b2084bd..1eace2db4 (1 commits)

https://skia.googlesource.com/skia.git/+log/50b2084bd..1eace2db4

2017-07-31 caryclark@skia.org fix capitalization

Test: Presubmit checks will test this change.
Change-Id: If7836a987bf19246a91bc0ce0fd6fceeacb0ff79