Renamed :host to :ancestor and made :host to match only shadow host.

Source/core/css/CSSTokenizer-in.cpp

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
@@ skipping 715 matching lines @@
             return true;
         }
         CASE("calc") {
             m_token = CALCFUNCTION;
             return true;
         }
         CASE("host") {
             m_token = HOSTFUNCTION;
             return true;
         }
+        CASE("ancestor") {
+            m_token = ANCESTORFUNCTION;
+            return true;
+        }
         CASE("nth-child") {
             m_parsingMode = NthChildMode;
             return true;
         }
         CASE("nth-of-type") {
             m_parsingMode = NthChildMode;
             return true;
         }
         CASE("nth-last-child") {
             m_parsingMode = NthChildMode;
@@ skipping 800 matching lines @@
     m_dataStart16[length - 1] = 0;
 
     m_is8BitSource = false;
     m_currentCharacter8 = 0;
     m_currentCharacter16 = m_dataStart16.get();
     setTokenStart<UChar>(m_currentCharacter16);
     m_lexFunc = &CSSTokenizer::realLex<UChar>;
 }
 
 } // namespace WebCore