Roll src/third_party/skia/ 39f053817..ff2103200 (3 commits).
Roll src/third_party/skia/ 39f053817..ff2103200 (3 commits).

https://chromium.googlesource.com/skia.git/+log/39f0538178bc..ff2103200bad

$ git log 39f053817..ff2103200 --date=short --no-merges --format='%ad %ae %s'
2015-11-24 ethannicholas New API for computing optimization invariants.
2015-11-24 reed optimize the disable-caching case for SkImage::readPixels
2015-11-24 borenet Whitespace change to trigger bots after gsutil change

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

Review URL: https://codereview.chromium.org/1477523002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#361451}

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