Roll src/third_party/WebKit 117dbc2:166b853 (svn 195420:195423)

Summary of changes available at:
https://chromium.googlesource.com/chromium/blink/+log/117dbc2..166b853

TBR=timvolodine@chromium.org,kbr@chromium.org

Review URL: https://codereview.chromium.org/1139543004

Cr-Commit-Position: refs/heads/master@{#330246}

DEPS

@@ -34,7 +34,7 @@ vars = {
   'llvm_url': 'http://src.chromium.org/llvm-project',
   'llvm_git': 'https://llvm.googlesource.com',
   'webkit_trunk': 'http://src.chromium.org/blink/trunk',
-  'webkit_revision': '117dbc2c497be4e52ff643575d6438febfa9053e', # from svn revision 195420
+  'webkit_revision': '166b8539e33a27e9901e040941f2661cdbe44b71', # from svn revision 195423
   'chromium_git': 'https://chromium.googlesource.com',
   'chromiumos_git': 'https://chromium.googlesource.com/chromiumos',
   'pdfium_git': 'https://pdfium.googlesource.com',