*** NOT FOR LANDING *** Unprefix multicol behind a flag

Source/core/css/parser/CSSPropertyParser.cpp

Index: Source/core/css/parser/CSSPropertyParser.cpp
diff --git a/Source/core/css/parser/CSSPropertyParser.cpp b/Source/core/css/parser/CSSPropertyParser.cpp
index 8708db5e2f520e111c93f0c4bf08c7aaedfef9eb..7dda3a94a0d71fc0cfba34b14c3abcfa92c8a0df 100644
--- a/Source/core/css/parser/CSSPropertyParser.cpp
+++ b/Source/core/css/parser/CSSPropertyParser.cpp
@@ -561,6 +561,10 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
             break;
         }
         /* nobreak */
+    case CSSPropertyColumnRuleColor:
+        if (propId == CSSPropertyColumnRuleColor && unresolvedProperty != CSSPropertyAliasWebkitColumnRuleColor && !inShorthand() && !RuntimeEnabledFeatures::unprefixMulticolEnabled())
+            return false;
+        /* nobreak */
     case CSSPropertyBackgroundColor: // <color> | inherit
     case CSSPropertyBorderTopColor: // <color> | inherit
     case CSSPropertyBorderRightColor:
@@ -572,7 +576,6 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
     case CSSPropertyWebkitBorderAfterColor:
     case CSSPropertyColor: // <color> | inherit
     case CSSPropertyTextDecorationColor: // CSS3 text decoration colors
-    case CSSPropertyWebkitColumnRuleColor:
     case CSSPropertyWebkitTextEmphasisColor:
     case CSSPropertyWebkitTextFillColor:
     case CSSPropertyWebkitTextStrokeColor:
@@ -769,13 +772,16 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
         if (!inShorthand() || m_currentShorthand == CSSPropertyBorderWidth)
             unitless = FUnitlessQuirk;
         // fall through
+    case CSSPropertyColumnRuleWidth:
+        if (propId == CSSPropertyColumnRuleWidth && unresolvedProperty != CSSPropertyAliasWebkitColumnRuleWidth && !inShorthand() && !RuntimeEnabledFeatures::unprefixMulticolEnabled())
+            return false;
+        // fall through
     case CSSPropertyWebkitTextStrokeWidth:
     case CSSPropertyOutlineWidth: // <border-width> | inherit
     case CSSPropertyWebkitBorderStartWidth:
     case CSSPropertyWebkitBorderEndWidth:
     case CSSPropertyWebkitBorderBeforeWidth:
     case CSSPropertyWebkitBorderAfterWidth:
-    case CSSPropertyWebkitColumnRuleWidth:
         if (id == CSSValueThin || id == CSSValueMedium || id == CSSValueThick)
             validPrimitive = true;
         else
@@ -1256,19 +1262,33 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
         }
         return false;
     }
-    case CSSPropertyWebkitColumnCount:
+    case CSSPropertyColumnCount:
+        if (unresolvedProperty != CSSPropertyAliasWebkitColumnCount && !inShorthand() && !RuntimeEnabledFeatures::unprefixMulticolEnabled())
+            return false;
         parsedValue = parseColumnCount();
         break;
-    case CSSPropertyWebkitColumnGap:         // normal | <length>
+    case CSSPropertyColumnGap: // normal | <length>
+        if (unresolvedProperty != CSSPropertyAliasWebkitColumnGap && !RuntimeEnabledFeatures::unprefixMulticolEnabled())
+            return false;
         if (id == CSSValueNormal)
             validPrimitive = true;
         else
             validPrimitive = validUnit(value, FLength | FNonNeg);
         break;
-    case CSSPropertyWebkitColumnSpan: // none | all | 1 (will be dropped in the unprefixed property)
+    case CSSPropertyColumnSpan: // none | all | 1 (will be dropped in the unprefixed property)
+        if (unresolvedProperty != CSSPropertyAliasWebkitColumnSpan && !RuntimeEnabledFeatures::unprefixMulticolEnabled())
+            return false;
         validPrimitive = id == CSSValueAll || id == CSSValueNone || (value->unit == CSSPrimitiveValue::CSS_NUMBER && value->fValue == 1);
         break;
-    case CSSPropertyWebkitColumnWidth:         // auto | <length>
+    case CSSPropertyColumnRuleStyle:
+        // TODO(mstensho): move this back into CSSParserFastPaths once we have shipped unprefixed multicol.
+        if (unresolvedProperty != CSSPropertyAliasWebkitColumnRuleStyle && !inShorthand() && !RuntimeEnabledFeatures::unprefixMulticolEnabled())
+            return false;
+        validPrimitive = id >= CSSValueNone && id <= CSSValueDouble;
+        break;
+    case CSSPropertyColumnWidth: // auto | <length>
+        if (unresolvedProperty != CSSPropertyAliasWebkitColumnWidth && !inShorthand() && !RuntimeEnabledFeatures::unprefixMulticolEnabled())
+            return false;
         parsedValue = parseColumnWidth();
         break;
     case CSSPropertyWillChange:
@@ -1400,10 +1420,14 @@ bool CSSPropertyParser::parseValue(CSSPropertyID unresolvedProperty, bool import
         return parseFont(important);
     case CSSPropertyListStyle:
         return parseShorthand(propId, listStyleShorthand(), important);
-    case CSSPropertyWebkitColumns:
+    case CSSPropertyColumns:
+        if (unresolvedProperty != CSSPropertyAliasWebkitColumns && !RuntimeEnabledFeatures::unprefixMulticolEnabled())
+            return false;
         return parseColumnsShorthand(important);
-    case CSSPropertyWebkitColumnRule:
-        return parseShorthand(propId, webkitColumnRuleShorthand(), important);
+    case CSSPropertyColumnRule:
+        if (unresolvedProperty != CSSPropertyAliasWebkitColumnRule && !RuntimeEnabledFeatures::unprefixMulticolEnabled())
+            return false;
+        return parseShorthand(propId, columnRuleShorthand(), important);
     case CSSPropertyWebkitTextStroke:
         return parseShorthand(propId, webkitTextStrokeShorthand(), important);
     case CSSPropertyAnimation:
@@ -1902,13 +1926,13 @@ bool CSSPropertyParser::parseColumnsShorthand(bool important)
 
     // Any unassigned property at this point will become implicit 'auto'.
     if (columnWidth)
-        addProperty(CSSPropertyWebkitColumnWidth, columnWidth, important);
+        addProperty(CSSPropertyColumnWidth, columnWidth, important);
     else
-        addProperty(CSSPropertyWebkitColumnWidth, cssValuePool().createIdentifierValue(CSSValueAuto), important, true /* implicit */);
+        addProperty(CSSPropertyColumnWidth, cssValuePool().createIdentifierValue(CSSValueAuto), important, true /* implicit */);
     if (columnCount)
-        addProperty(CSSPropertyWebkitColumnCount, columnCount, important);
+        addProperty(CSSPropertyColumnCount, columnCount, important);
     else
-        addProperty(CSSPropertyWebkitColumnCount, cssValuePool().createIdentifierValue(CSSValueAuto), important, true /* implicit */);
+        addProperty(CSSPropertyColumnCount, cssValuePool().createIdentifierValue(CSSValueAuto), important, true /* implicit */);
     return true;
 }