Roll src/third_party/skia/ e918417dc..4d450d24f (4 commits).

https://chromium.googlesource.com/skia.git/+log/e918417dc34c..4d450d24f5a7

$ git log e918417dc..4d450d24f --date=short --no-merges --format='%ad %ae %s'
2016-09-20 bungeman Remove SK_ADDING_src_ports_SkFontConfigInterface_cpp
2016-09-20 fmalita [SVGDom] Opacity optimization
2016-09-20 mtklein Blacklist serialize-8888 typefacerendering_pfaMac
2016-09-20 mtklein GN: fold :vulkan into :gpu.

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

Review-Url: https://codereview.chromium.org/2354993004
Cr-Commit-Position: refs/heads/master@{#419937}

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': 'e918417dc34c0856822e6955b788e962c289ca3d',
+  'skia_revision': '4d450d24f5a7e60015fb34de998da2bf46196d46',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling V8
   # and whatever else without interference from each other.