[WIP] CSS Motion Path: offset shorthand ready for position and anchor

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

Index: third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
diff --git a/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp b/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
index d95f1f656d63f77101dd2168c2af526c5b1cb519..b567f5aee7aabc12bc591b954182986c88939fb2 100644
--- a/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
+++ b/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
@@ -448,6 +448,22 @@ static CSSValueList* valueForItemPositionWithOverflowAlignment(const StyleSelfAl
     return result;
 }
 
+static CSSValue* valueForOffsetPath(const StylePath* styleMotionPath)
+{
+    if (styleMotionPath)
+        return styleMotionPath->computedCSSValue();
+    return CSSPrimitiveValue::createIdentifier(CSSValueNone);
+}
+
+static CSSValue* valueForOffsetRotation(const StyleOffsetRotation& offsetRotation)
+{
+    CSSValueList* list = CSSValueList::createSpaceSeparated();
+    if (offsetRotation.type == OffsetRotationAuto)
+        list->append(*CSSPrimitiveValue::createIdentifier(CSSValueAuto));
+    list->append(*CSSPrimitiveValue::create(offsetRotation.angle, CSSPrimitiveValue::UnitType::Degrees));
+    return list;
+}
+
 static CSSValueList* valuesForGridShorthand(const StylePropertyShorthand& shorthand, const ComputedStyle& style, const LayoutObject* layoutObject, Node* styledNode, bool allowVisitedStyle)
 {
     CSSValueList* list = CSSValueList::createSlashSeparated();
@@ -1574,6 +1590,28 @@ CSSValue* ComputedStyleCSSValueMapping::valueForFont(const ComputedStyle& style)
     return list;
 }
 
+CSSValue* ComputedStyleCSSValueMapping::valueForOffset(const ComputedStyle& style)
+{
+    CSSValueList* list = CSSValueList::createSpaceSeparated();
+    if (style.offsetPosition() != ComputedStyle::initialOffsetPosition()) {
+        DCHECK(RuntimeEnabledFeatures::cssOffsetPositionAnchorEnabled());
+        list->append(*valueForPosition(style.offsetPosition(), style));
+    }
+
+    list->append(*valueForOffsetPath(style.offsetPath()));
+    list->append(*zoomAdjustedPixelValueForLength(style.offsetDistance(), style));
+    list->append(*valueForOffsetRotation(style.offsetRotation()));
+
+    if (style.offsetAnchor() == ComputedStyle::initialOffsetAnchor())
+        return list;
+
+    DCHECK(RuntimeEnabledFeatures::cssOffsetPositionAnchorEnabled());
+    CSSValueList* outerList = CSSValueList::createSlashSeparated();
+    outerList->append(*list);
+    outerList->append(*valueForPosition(style.offsetAnchor(), style));
+    return outerList;
+}
+
 static CSSValue* valueForScrollSnapDestination(const LengthPoint& destination, const ComputedStyle& style)
 {
     CSSValueList* list = CSSValueList::createSpaceSeparated();
@@ -2743,7 +2781,7 @@ const CSSValue* ComputedStyleCSSValueMapping::get(CSSPropertyID propertyID, cons
         return valuesForShorthandProperty(motionShorthand(), style, layoutObject, styledNode, allowVisitedStyle);
 
     case CSSPropertyOffset:
-        return valuesForShorthandProperty(offsetShorthand(), style, layoutObject, styledNode, allowVisitedStyle);
+        return valueForOffset(style);
 
     case CSSPropertyOffsetAnchor:
         return valueForPosition(style.offsetAnchor(), style);
@@ -2752,20 +2790,13 @@ const CSSValue* ComputedStyleCSSValueMapping::get(CSSPropertyID propertyID, cons
         return valueForPosition(style.offsetPosition(), style);
 
     case CSSPropertyOffsetPath:
-        if (const StylePath* styleMotionPath = style.offsetPath())
-            return styleMotionPath->computedCSSValue();
-        return CSSPrimitiveValue::createIdentifier(CSSValueNone);
+        return valueForOffsetPath(style.offsetPath());
 
     case CSSPropertyOffsetDistance:
         return zoomAdjustedPixelValueForLength(style.offsetDistance(), style);
 
-    case CSSPropertyOffsetRotation: {
-        CSSValueList* list = CSSValueList::createSpaceSeparated();
-        if (style.offsetRotation().type == OffsetRotationAuto)
-            list->append(*CSSPrimitiveValue::createIdentifier(CSSValueAuto));
-        list->append(*CSSPrimitiveValue::create(style.offsetRotation().angle, CSSPrimitiveValue::UnitType::Degrees));
-        return list;
-    }
+    case CSSPropertyOffsetRotation:
+        return valueForOffsetRotation(style.offsetRotation());
 
     // Unimplemented CSS 3 properties (including CSS3 shorthand properties).
     case CSSPropertyWebkitTextEmphasis: