Roll src/third_party/skia/ 727b7d27a..f42fca402 (2 commits).

https://chromium.googlesource.com/skia.git/+log/727b7d27afd0..f42fca4027ed

$ git log 727b7d27a..f42fca402 --date=short --no-merges --format='%ad %ae %s'
2016-01-27 robertphillips Add gpu implementation of OverdrawXfermode GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1607253002
2016-01-26 caryclark move more geometry to simd

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

Review URL: https://codereview.chromium.org/1639303002

Cr-Commit-Position: refs/heads/master@{#371793}

DEPS

@@ -39,7 +39,7 @@ 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': '727b7d27afd01ab76771ba0b3279208cff728d1a',
+  'skia_revision': 'f42fca4027ed4f235ef927786813a5ed0e6652b9',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.