Ribbon: Support CSSUnresolvedProperty in CSSPropertyRef.

This makes it possible to use CSSPropertyRef to get instances which
represent aliases.

R=futhark@chromium.org

Change-Id: I6098c02678bb36bb08ecb28764893245e747a350
Reviewed-on: https://chromium-review.googlesource.com/c/1323111
Commit-Queue: Anders Ruud <andruud@chromium.org>
Reviewed-by: Rune Lillesveen <futhark@chromium.org>
Cr-Commit-Position: refs/heads/master@{#606460}

third_party/blink/renderer/core/css/properties/css_property_ref.cc

@@ -9,7 +9,7 @@
 namespace blink {
 
 CSSPropertyRef::CSSPropertyRef(const String& name, const Document& document)
-    : property_id_(cssPropertyID(name)) {
+    : property_id_(unresolvedCSSPropertyID(name)) {
   if (property_id_ == CSSPropertyVariable)
     custom_property_ = CustomProperty(AtomicString(name), document);
 }

third_party/blink/renderer/core/css/properties/css_property_ref.h

@@ -52,7 +52,13 @@ class CORE_EXPORT CSSPropertyRef {
     DCHECK(IsValid());
     if (property_id_ == CSSPropertyVariable)
       return custom_property_;
-    return CSSProperty::Get(property_id_);
+    return CSSProperty::Get(resolveCSSPropertyID(property_id_));
+  }
+
+  const CSSUnresolvedProperty& GetUnresolvedProperty() const {
+    if (isPropertyAlias(property_id_))
+      return *CSSUnresolvedProperty::GetAliasProperty(property_id_);
+    return GetProperty();
   }
 
   void Trace(blink::Visitor* visitor) { visitor->Trace(custom_property_); }

third_party/blink/renderer/core/css/properties/css_property_ref_test.cc

@@ -75,4 +75,29 @@ TEST_F(CSSPropertyRefTest, FromStaticVariableInstance) {
   EXPECT_FALSE(ref.IsValid());
 }
 
+TEST_F(CSSPropertyRefTest, GetUnresolvedPropertyStandard) {
+  CSSPropertyRef ref("font-size", GetDocument());
+  EXPECT_TRUE(ref.GetUnresolvedProperty().IsResolvedProperty());
+}
+
+TEST_F(CSSPropertyRefTest, GetUnresolvedPropertyCustom) {
+  CSSPropertyRef ref("--x", GetDocument());
+  EXPECT_TRUE(ref.GetUnresolvedProperty().IsResolvedProperty());
+}
+
+TEST_F(CSSPropertyRefTest, GetUnresolvedPropertyAlias) {
+  // -webkit-transform is an arbitrarily chosen alias.
+  CSSPropertyRef ref("-webkit-transform", GetDocument());
+  const auto& unresolved = ref.GetUnresolvedProperty();
+  EXPECT_FALSE(unresolved.IsResolvedProperty());
+  EXPECT_EQ("-webkit-transform", unresolved.GetPropertyNameString());
+}
+
+TEST_F(CSSPropertyRefTest, GetResolvedPropertyAlias) {
+  // -webkit-transform is an arbitrarily chosen alias.
+  CSSPropertyRef ref("-webkit-transform", GetDocument());
+  EXPECT_TRUE(ref.GetProperty().IsResolvedProperty());
+  EXPECT_EQ("transform", ref.GetProperty().GetPropertyNameString());
+}
+
 }  // namespace blink