Roll src/third_party/skia/ da19f6f3b..ae6377c08 (6 commits).

https://chromium.googlesource.com/skia.git/+log/da19f6f3b5f1..ae6377c08e5c

$ git log da19f6f3b..ae6377c08 --date=short --no-merges --format='%ad %ae %s'
2016-08-23 msarett Make singleton SkColorSpaces thread safe
2016-08-23 bsalomon Remove SkPixelRef::getTexture() GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2264293003
2016-08-23 mtklein GN: extract optional() as a template and use for giflib-dependent code
2016-08-23 mtklein GN: Fix up Ganesh native interface hooks.
2016-08-23 csmartdalton Skip non-AA intersect rects in GrReducedClip
2016-08-23 bungeman SkScalerContextRec::computeMatrices to return status.

BUG=630169

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_precise_blink_rel
TBR=bungeman@google.com

Review-Url: https://codereview.chromium.org/2274773002
Cr-Commit-Position: refs/heads/master@{#413930}

DEPS

@@ -36,7 +36,7 @@ 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': 'da19f6f3b5f1375c854a9bde947c12099afc25c7',
+  'skia_revision': 'ae6377c08e5c3735c65212ba9ff86fa51af7d68a',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.