Roll src/third_party/skia/ 621ea115e..0c2997b6d (4 commits).

https://skia.googlesource.com/skia.git/+log/621ea115e0b1..0c2997b6d85e

$ git log 621ea115e..0c2997b6d --date=short --no-merges --format='%ad %ae %s'
2017-01-11 brianosman Remove second version of SkImageInfo2GrPixelConfig
2017-01-11 brianosman Remove kIndex_8_GrPixelConfig
2017-01-12 borenet Move recipe expectations into example.py recipes inside of modules
2017-01-12 borenet Move most recipes into modules

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+/master/autoroll/README.md

If the roll is causing failures, see:
http://www.chromium.org/developers/tree-sheriffs/sheriff-details-chromium#TOC-Failures-due-to-DEPS-rolls

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel
TBR=kjlubick@google.com

Review-Url: https://codereview.chromium.org/2630543002
Cr-Commit-Position: refs/heads/master@{#443242}

DEPS

@@ -40,7 +40,7 @@ vars = {
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling Skia
   # and whatever else without interference from each other.
-  'skia_revision': '621ea115e0b14467ae8f410ed6ad7a31bbe224e2',
+  'skia_revision': '0c2997b6d85e381e63e3af98245a87bf04753681',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.