Add CSS parser support for the snap-height property

third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp

 /*
  * Copyright (C) 2004 Zack Rusin <zack@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alexey Proskuryakov <ap@webkit.org>
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2011 Sencha, Inc. All rights reserved.
  * Copyright (C) 2015 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ skipping 2679 matching lines @@
         RefPtrWillBeRawPtr<CSSValueList> list = CSSValueList::createSpaceSeparated();
         if (style.containsStyle())
             list->append(cssValuePool().createIdentifierValue(CSSValueStyle));
         if (style.contain() & ContainsLayout)
             list->append(cssValuePool().createIdentifierValue(CSSValueLayout));
         if (style.containsPaint())
             list->append(cssValuePool().createIdentifierValue(CSSValuePaint));
         ASSERT(list->length());
         return list.release();
     }
+    case CSSPropertySnapHeight: {
+        if (!style.snapHeightUnit())
+            return cssValuePool().createValue(0, CSSPrimitiveValue::UnitType::Pixels);
+        RefPtrWillBeRawPtr<CSSValueList> list = CSSValueList::createSpaceSeparated();
+        list->append(cssValuePool().createValue(style.snapHeightUnit(), CSSPrimitiveValue::UnitType::Pixels));
+        if (style.snapHeightPosition())
+            list->append(cssValuePool().createValue(style.snapHeightPosition(), CSSPrimitiveValue::UnitType::Integer));
+        return list.release();
+    }
     case CSSPropertyVariable:
         // Variables are retrieved via get(AtomicString).
         ASSERT_NOT_REACHED();
         return nullptr;
     case CSSPropertyAll:
         return nullptr;
     default:
         break;
     }
     ASSERT_NOT_REACHED();
     return nullptr;
 }
 
 } // namespace blink