Remove support for -webkit-line-clamp

Source/core/css/CSSProperty.cpp

 /**
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 578 matching lines @@
     case CSSPropertyGridColumn:
     case CSSPropertyGridColumnEnd:
     case CSSPropertyGridColumnStart:
     case CSSPropertyGridDefinitionColumns:
     case CSSPropertyGridDefinitionRows:
     case CSSPropertyGridRow:
     case CSSPropertyGridRowEnd:
     case CSSPropertyGridRowStart:
     case CSSPropertyGridTemplate:
     case CSSPropertyJustifyContent:
-    case CSSPropertyWebkitLineClamp:
     case CSSPropertyWebkitLogicalHeight:
     case CSSPropertyWebkitLogicalWidth:
     case CSSPropertyWebkitMarginAfter:
     case CSSPropertyWebkitMarginAfterCollapse:
     case CSSPropertyWebkitMarginBefore:
     case CSSPropertyWebkitMarginBeforeCollapse:
     case CSSPropertyWebkitMarginBottomCollapse:
     case CSSPropertyWebkitMarginCollapse:
     case CSSPropertyWebkitMarginEnd:
     case CSSPropertyWebkitMarginStart:
@@ skipping 70 matching lines @@
         return false;
     case CSSPropertyInvalid:
         ASSERT_NOT_REACHED();
         return false;
     }
     ASSERT_NOT_REACHED();
     return false;
 }
 
 } // namespace WebCore