Add support for the object-fit CSS property.

Source/core/css/CSSPrimitiveValueMappings.h

Index: Source/core/css/CSSPrimitiveValueMappings.h
diff --git a/Source/core/css/CSSPrimitiveValueMappings.h b/Source/core/css/CSSPrimitiveValueMappings.h
index 394702c43a05622a775f8b750e0d4829b5378e4b..ad4d492e3aee925688ede19809fba43e9a4b78ab 100644
--- a/Source/core/css/CSSPrimitiveValueMappings.h
+++ b/Source/core/css/CSSPrimitiveValueMappings.h
@@ -3359,6 +3359,48 @@ template<> inline CSSPrimitiveValue::operator FontDescription::Kerning() const
     return FontDescription::AutoKerning;
 }
 
+template<> inline CSSPrimitiveValue::CSSPrimitiveValue(EObjectFit e)
+    : CSSValue(PrimitiveClass)
+{
+    m_primitiveUnitType = CSS_VALUE_ID;
+    switch (e) {
+    case ObjectFitFill:
+        m_value.valueID = CSSValueFill;
+        break;
+    case ObjectFitContain:
+        m_value.valueID = CSSValueContain;
+        break;
+    case ObjectFitCover:
+        m_value.valueID = CSSValueCover;
+        break;
+    case ObjectFitNone:
+        m_value.valueID = CSSValueNone;
+        break;
+    case ObjectFitScaleDown:
+        m_value.valueID = CSSValueScaleDown;
+        break;
+    }
+}
+
+template<> inline CSSPrimitiveValue::operator EObjectFit() const
+{
+    switch (m_value.valueID) {
+    case CSSValueFill:
+        return ObjectFitFill;
+    case CSSValueContain:
+        return ObjectFitContain;
+    case CSSValueCover:
+        return ObjectFitCover;
+    case CSSValueNone:
+        return ObjectFitNone;
+    case CSSValueScaleDown:
+        return ObjectFitScaleDown;
+    default:
+        ASSERT_NOT_REACHED();
+        return ObjectFitFill;
+    }
+}
+
 template<> inline CSSPrimitiveValue::CSSPrimitiveValue(FontSmoothingMode smoothing)
     : CSSValue(PrimitiveClass)
 {