Roll external/skia ade9f618e..610842af9 (2 commits)

https://skia.googlesource.com/skia.git/+log/ade9f618e..610842af9

2017-06-16 bsalomon@google.com Make SkTArray maintain reserve count
2017-06-16 robertphillips@google.com Hide GrGpuResourceRef from prying eyes

Test: Presubmit checks will test this change.
Change-Id: I3eebd9c92d069cd03761b68c4fbdf152d6bf48e7