Roll src/third_party/skia/ 848904e5b..fe2042e60 (4 commits).

https://chromium.googlesource.com/skia.git/+log/848904e5b356..fe2042e60fa7

$ git log 848904e5b..fe2042e60 --date=short --no-merges --format='%ad %ae %s'
2016-07-29 mtklein SkRasterPipeline: new APIs for fusion
2016-07-29 mtklein simplify neon shifts
2016-07-29 bsalomon If scissor would be empty in GrClipMaskManager::SetupClipping indicate draw can be skipped.
2016-07-29 csmartdalton Add ES 3.0 fallback for instanced rendering

BUG=632185

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

Review-Url: https://codereview.chromium.org/2201533002
Cr-Commit-Position: refs/heads/master@{#408831}

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': '848904e5b356ac427ccf68f8a39837e52fa61059',
+  'skia_revision': 'fe2042e60fa7382461a45b1de0a02d345009f468',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.