Revert 255694 "Blink roll 168699:168744"

Fails to compile on "Android Webview AOSP Builder"

http://build.chromium.org/p/chromium.linux/builders/Android%20Webview%20AOSP%20Builder/builds/9360

> Blink roll 168699:168744
> 
> http://build.chromium.org/f/chromium/perf/dashboard/ui/changelog_blink.html?url=/trunk&range=168700:168744&mode=html
> TBR=
> BUG=
> 
> Review URL: https://codereview.chromium.org/190633004

TBR=arv@chromium.org

Review URL: https://codereview.chromium.org/189373011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255701 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -23,7 +23,7 @@ vars = {
   "libcxxabi_revision": "197063",
   "webkit_trunk": "http://src.chromium.org/blink/trunk",
   "nacl_trunk": "http://src.chromium.org/native_client/trunk",
-  "webkit_revision": "168744",
+  "webkit_revision": "168699",
   "chromium_git": "https://chromium.googlesource.com",
   "chromiumos_git": "https://chromium.googlesource.com/chromiumos",
   "skia_git": "https://skia.googlesource.com",