Revert of Blink roll 166855:166873 (https://codereview.chromium.org/1…

…51433006/)

Reason for revert:
Breaks Chrome OS buildbots:

http://build.chromium.org/p/chromium.chromiumos/buildstatus?builder=ChromiumOS%20%28x86%29&number=19788

http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%28dbg%29%283%29/builds/33358

Original issue's description:
> Blink roll 166855:166873
> 
> http://build.chromium.org/f/chromium/perf/dashboard/ui/changelog_blink.html?url=/trunk&range=166856:166873&mode=html
> TBR=
> BUG=
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=250324

TBR=eseidel@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=

Review URL: https://codereview.chromium.org/154113009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250374 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -23,7 +23,7 @@ vars = {
   "libcxxabi_revision": "753a30dd68ae008948d48f16bc942d5963fe65a1",
   "webkit_trunk": "http://src.chromium.org/blink/trunk",
   "nacl_trunk": "http://src.chromium.org/native_client/trunk",
-  "webkit_revision": "166873",
+  "webkit_revision": "166855",
   "chromium_git": "https://chromium.googlesource.com",
   "chromiumos_git": "https://chromium.googlesource.com/chromiumos",
   "skia_git": "https://skia.googlesource.com",