--- a/layout/style/nsComputedDOMStyle.cpp
+++ b/layout/style/nsComputedDOMStyle.cpp
@@ -2101,19 +2101,21 @@ nsComputedDOMStyle::DoGetFontSynthesis()
 
   int32_t intValue = StyleFont()->mFont.synthesis;
 
   if (0 == intValue) {
     val->SetIdent(eCSSKeyword_none);
   } else {
     nsAutoString valueStr;
 
-    nsStyleUtil::AppendBitmaskCSSValue(eCSSProperty_font_synthesis,
-      intValue, NS_FONT_SYNTHESIS_WEIGHT,
-      NS_FONT_SYNTHESIS_STYLE, valueStr);
+    nsStyleUtil::AppendBitmaskCSSValue(nsCSSProps::kFontSynthesisKTable,
+                                       intValue,
+                                       NS_FONT_SYNTHESIS_WEIGHT,
+                                       NS_FONT_SYNTHESIS_STYLE,
+                                       valueStr);
     val->SetString(valueStr);
   }
 
   return val.forget();
 }
 
 // return a value *only* for valid longhand values from CSS 2.1, either
 // normal or small-caps only
@@ -2156,17 +2158,18 @@ nsComputedDOMStyle::DoGetFontVariantAlte
   if (0 == intValue) {
     val->SetIdent(eCSSKeyword_normal);
     return val.forget();
   }
 
   // first, include enumerated values
   nsAutoString valueStr;
 
-  nsStyleUtil::AppendBitmaskCSSValue(eCSSProperty_font_variant_alternates,
+  nsStyleUtil::AppendBitmaskCSSValue(
+    nsCSSProps::kFontVariantAlternatesKTable,
     intValue & NS_FONT_VARIANT_ALTERNATES_ENUMERATED_MASK,
     NS_FONT_VARIANT_ALTERNATES_HISTORICAL,
     NS_FONT_VARIANT_ALTERNATES_HISTORICAL, valueStr);
 
   // next, include functional values if present
   if (intValue & NS_FONT_VARIANT_ALTERNATES_FUNCTIONAL_MASK) {
     nsStyleUtil::SerializeFunctionalAlternates(StyleFont()->mFont.alternateValues,
                                                valueStr);
@@ -2201,19 +2204,21 @@ nsComputedDOMStyle::DoGetFontVariantEast
 
   int32_t intValue = StyleFont()->mFont.variantEastAsian;
 
   if (0 == intValue) {
     val->SetIdent(eCSSKeyword_normal);
   } else {
     nsAutoString valueStr;
 
-    nsStyleUtil::AppendBitmaskCSSValue(eCSSProperty_font_variant_east_asian,
-      intValue, NS_FONT_VARIANT_EAST_ASIAN_JIS78,
-      NS_FONT_VARIANT_EAST_ASIAN_RUBY, valueStr);
+    nsStyleUtil::AppendBitmaskCSSValue(nsCSSProps::kFontVariantEastAsianKTable,
+                                       intValue,
+                                       NS_FONT_VARIANT_EAST_ASIAN_JIS78,
+                                       NS_FONT_VARIANT_EAST_ASIAN_RUBY,
+                                       valueStr);
     val->SetString(valueStr);
   }
 
   return val.forget();
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetFontVariantLigatures()
@@ -2224,19 +2229,21 @@ nsComputedDOMStyle::DoGetFontVariantLiga
 
   if (0 == intValue) {
     val->SetIdent(eCSSKeyword_normal);
   } else if (NS_FONT_VARIANT_LIGATURES_NONE == intValue) {
     val->SetIdent(eCSSKeyword_none);
   } else {
     nsAutoString valueStr;
 
-    nsStyleUtil::AppendBitmaskCSSValue(eCSSProperty_font_variant_ligatures,
-      intValue, NS_FONT_VARIANT_LIGATURES_NONE,
-      NS_FONT_VARIANT_LIGATURES_NO_CONTEXTUAL, valueStr);
+    nsStyleUtil::AppendBitmaskCSSValue(nsCSSProps::kFontVariantLigaturesKTable,
+                                       intValue,
+                                       NS_FONT_VARIANT_LIGATURES_NONE,
+                                       NS_FONT_VARIANT_LIGATURES_NO_CONTEXTUAL,
+                                       valueStr);
     val->SetString(valueStr);
   }
 
   return val.forget();
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetFontVariantNumeric()
@@ -2245,19 +2252,21 @@ nsComputedDOMStyle::DoGetFontVariantNume
 
   int32_t intValue = StyleFont()->mFont.variantNumeric;
 
   if (0 == intValue) {
     val->SetIdent(eCSSKeyword_normal);
   } else {
     nsAutoString valueStr;
 
-    nsStyleUtil::AppendBitmaskCSSValue(eCSSProperty_font_variant_numeric,
-      intValue, NS_FONT_VARIANT_NUMERIC_LINING,
-      NS_FONT_VARIANT_NUMERIC_ORDINAL, valueStr);
+    nsStyleUtil::AppendBitmaskCSSValue(nsCSSProps::kFontVariantNumericKTable,
+                                       intValue,
+                                       NS_FONT_VARIANT_NUMERIC_LINING,
+                                       NS_FONT_VARIANT_NUMERIC_ORDINAL,
+                                       valueStr);
     val->SetString(valueStr);
   }
 
   return val.forget();
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetFontVariantPosition()
@@ -3292,17 +3301,17 @@ nsComputedDOMStyle::GetGridTemplateColum
 
   return valueList.forget();
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetGridAutoFlow()
 {
   nsAutoString str;
-  nsStyleUtil::AppendBitmaskCSSValue(eCSSProperty_grid_auto_flow,
+  nsStyleUtil::AppendBitmaskCSSValue(nsCSSProps::kGridAutoFlowKTable,
                                      StylePosition()->mGridAutoFlow,
                                      NS_STYLE_GRID_AUTO_FLOW_ROW,
                                      NS_STYLE_GRID_AUTO_FLOW_DENSE,
                                      str);
   RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
   val->SetString(str);
   return val.forget();
 }
@@ -4203,19 +4212,21 @@ nsComputedDOMStyle::DoGetTextDecorationL
 
   if (NS_STYLE_TEXT_DECORATION_LINE_NONE == intValue) {
     val->SetIdent(eCSSKeyword_none);
   } else {
     nsAutoString decorationLineString;
     // Clear the OVERRIDE_ALL bits -- we don't want these to appear in
     // the computed style.
     intValue &= ~NS_STYLE_TEXT_DECORATION_LINE_OVERRIDE_ALL;
-    nsStyleUtil::AppendBitmaskCSSValue(eCSSProperty_text_decoration_line,
-      intValue, NS_STYLE_TEXT_DECORATION_LINE_UNDERLINE,
-      NS_STYLE_TEXT_DECORATION_LINE_BLINK, decorationLineString);
+    nsStyleUtil::AppendBitmaskCSSValue(nsCSSProps::kTextDecorationLineKTable,
+                                       intValue,
+                                       NS_STYLE_TEXT_DECORATION_LINE_UNDERLINE,
+                                       NS_STYLE_TEXT_DECORATION_LINE_BLINK,
+                                       decorationLineString);
     val->SetString(decorationLineString);
   }
 
   return val.forget();
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetTextDecorationStyle()
@@ -5052,17 +5063,17 @@ nsComputedDOMStyle::DoGetContain()
     val->SetIdent(eCSSKeyword_none);
   } else if (mask & NS_STYLE_CONTAIN_STRICT) {
     NS_ASSERTION(mask == (NS_STYLE_CONTAIN_STRICT | NS_STYLE_CONTAIN_ALL_BITS),
                  "contain: strict should imply contain: layout style paint");
     val->SetIdent(eCSSKeyword_strict);
   } else {
     nsAutoString valueStr;
 
-    nsStyleUtil::AppendBitmaskCSSValue(eCSSProperty_contain,
+    nsStyleUtil::AppendBitmaskCSSValue(nsCSSProps::kContainKTable,
                                        mask, NS_STYLE_CONTAIN_LAYOUT,
                                        NS_STYLE_CONTAIN_PAINT, valueStr);
     val->SetString(valueStr);
   }
 
   return val.forget();
 }
 
@@ -5262,19 +5273,21 @@ nsComputedDOMStyle::DoGetTouchAction()
   RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;
 
   int32_t intValue = StyleDisplay()->mTouchAction;
 
   // None and Auto and Manipulation values aren't allowed
   // to be in conjunction with other values.
   // But there are all checks in CSSParserImpl::ParseTouchAction
   nsAutoString valueStr;
-  nsStyleUtil::AppendBitmaskCSSValue(eCSSProperty_touch_action, intValue,
-    NS_STYLE_TOUCH_ACTION_NONE, NS_STYLE_TOUCH_ACTION_MANIPULATION,
-    valueStr);
+  nsStyleUtil::AppendBitmaskCSSValue(nsCSSProps::kTouchActionKTable,
+                                     intValue,
+                                     NS_STYLE_TOUCH_ACTION_NONE,
+                                     NS_STYLE_TOUCH_ACTION_MANIPULATION,
+                                     valueStr);
   val->SetString(valueStr);
   return val.forget();
 }
 
 already_AddRefed<CSSValue>
 nsComputedDOMStyle::DoGetHeight()
 {
   RefPtr<nsROCSSPrimitiveValue> val = new nsROCSSPrimitiveValue;

--- a/layout/style/nsStyleUtil.cpp
+++ b/layout/style/nsStyleUtil.cpp
@@ -247,26 +247,25 @@ nsStyleUtil::AppendEscapedCSSFontFamilyL
     return;
   }
 
   AppendEscapedCSSFontFamilyList(aFamilyList.GetFontlist().get(), aResult);
 }
 
 
 /* static */ void
-nsStyleUtil::AppendBitmaskCSSValue(nsCSSPropertyID aProperty,
+nsStyleUtil::AppendBitmaskCSSValue(const nsCSSKTableEntry aTable[],
                                    int32_t aMaskedValue,
                                    int32_t aFirstMask,
                                    int32_t aLastMask,
                                    nsAString& aResult)
 {
   for (int32_t mask = aFirstMask; mask <= aLastMask; mask <<= 1) {
     if (mask & aMaskedValue) {
-      AppendASCIItoUTF16(nsCSSProps::LookupPropertyValue(aProperty, mask),
-                         aResult);
+      AppendASCIItoUTF16(nsCSSProps::ValueToKeyword(mask, aTable), aResult);
       aMaskedValue &= ~mask;
       if (aMaskedValue) { // more left
         aResult.Append(char16_t(' '));
       }
     }
   }
   MOZ_ASSERT(aMaskedValue == 0, "unexpected bit remaining in bitfield");
 }

--- a/layout/style/nsStyleUtil.h
+++ b/layout/style/nsStyleUtil.h
@@ -16,16 +16,17 @@
 
 class nsCSSValue;
 class nsStyleCoord;
 class nsIContent;
 class nsIPrincipal;
 class nsIURI;
 struct gfxFontFeature;
 struct gfxAlternateValue;
+struct nsCSSKTableEntry;
 struct nsCSSValueList;
 
 namespace mozilla {
 class FontSlantStyle;
 }
 
 // Style utility functions
 class nsStyleUtil {
@@ -67,17 +68,17 @@ public:
 
 private:
   static void
   AppendEscapedCSSFontFamilyList(const nsTArray<mozilla::FontFamilyName>& aNames,
                                  nsAString& aResult);
 
 public:
   // Append a bitmask-valued property's value(s) (space-separated) to aResult.
-  static void AppendBitmaskCSSValue(nsCSSPropertyID aProperty,
+  static void AppendBitmaskCSSValue(const nsCSSKTableEntry aTable[],
                                     int32_t aMaskedValue,
                                     int32_t aFirstMask,
                                     int32_t aLastMask,
                                     nsAString& aResult);
 
   static void AppendAngleValue(const nsStyleCoord& aValue, nsAString& aResult);
 
   static void AppendPaintOrderValue(uint8_t aValue, nsAString& aResult);