Roll src/third_party/skia/ 58cda8fa4..93f1633ab (1 commit).

https://skia.googlesource.com/skia.git/+log/58cda8fa4952..93f1633abca9

$ git log 58cda8fa4..93f1633ab --date=short --no-merges --format='%ad %ae %s'
2016-11-23 robertphillips Fix gpu blurring on platforms that "useDrawInsteadOfClear"

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=egdaniel@google.com

Review-Url: https://codereview.chromium.org/2531763003
Cr-Commit-Position: refs/heads/master@{#434561}

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': '58cda8fa495225bbcb3d93bdd7f81ec515402475',
+  'skia_revision': '93f1633abca95e302fdd31ece0f4d602b0b26708',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.