Roll src/third_party/skia 73fa616:518a292

Roll src/third_party/skia 73fa616:518a292

Summary of changes available at:
https://chromium.googlesource.com/skia/+log/73fa616..518a292

CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel
TBR=msarett@google.com

Commits in this roll:
518a292 mtklein@chromium.org Stop using SkScalerContext::getAdvance() in SkGlyphCache.
86e90fa reed@google.com add preroll to image, for chrome's warmup pass
12d40c1 mtklein@chromium.org Restore old NEON blit_mask_d32_a8 methods.
c911906 halcanary@google.com Documentation: C API comments
2a4a421 halcanary@google.com Cmake: fix to make linking work on Ubuntu
219f18f halcanary@google.com C API: Add SK_API, also documentation of an example.

Review URL: https://codereview.chromium.org/1312943004

Cr-Commit-Position: refs/heads/master@{#346731}