Roll src/third_party/skia/ 4c7e117b6..494c2b6fa (3 commits).

https://chromium.googlesource.com/skia.git/+log/4c7e117b696b..494c2b6fa125

$ git log 4c7e117b6..494c2b6fa --date=short --no-merges --format='%ad %ae %s'
2016-07-14 herb Fix a bug in the Clamp in X direction tiling. The code mixed up which end of the span was cut and preserved in the sequence of span breaks.
2016-07-14 robertphillips Remove GrWrapTextureInBitmap call in SkGpuDevice::drawSpriteWithFilter
2016-07-14 fmalita Build Expat on all platforms

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

Review-Url: https://codereview.chromium.org/2153433003
Cr-Commit-Position: refs/heads/master@{#405617}

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': '4c7e117b696b67d45dc939e8b516f6ae18e68d1a',
+  'skia_revision': '494c2b6fa125d85d99fb6e9b479f21f4f76c32bb',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.