Roll src/third_party/skia/ cb232e8b1..5f80e8cb7 (3 commits).
Roll src/third_party/skia/ cb232e8b1..5f80e8cb7 (3 commits).

https://chromium.googlesource.com/skia.git/+log/cb232e8b1b9f..5f80e8cb7cfb

$ git log cb232e8b1..5f80e8cb7 --date=short --no-merges --format='%ad %ae %s'
2016-04-18 rmistry Walk through files in parse_llvm_coverage.py instead of using 'git ls-files'
2016-04-18 rmistry Do not do compile steps for Coverage
2016-04-18 rmistry Add new coverage_skia.isolate

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

Review URL: https://codereview.chromium.org/1897803002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#387897}

axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk,axinging/chromium-crosswalk