CSS Transforms: Implement perspective-origin

Source/core/css/resolver/AnimatedStyleBuilder.cpp

Index: Source/core/css/resolver/AnimatedStyleBuilder.cpp
diff --git a/Source/core/css/resolver/AnimatedStyleBuilder.cpp b/Source/core/css/resolver/AnimatedStyleBuilder.cpp
index 0625d585496e54d3b66afc4a095bd36584ee154c..70f32003369f202a419288cb73929848d5e4f494 100644
--- a/Source/core/css/resolver/AnimatedStyleBuilder.cpp
+++ b/Source/core/css/resolver/AnimatedStyleBuilder.cpp
@@ -557,10 +557,19 @@ void AnimatedStyleBuilder::applyProperty(CSSPropertyID property, StyleResolverSt
     case CSSPropertyPerspective:
         style->setPerspective(clampTo<float>(toAnimatableDouble(value)->toDouble()));
         return;
+    case CSSPropertyPerspectiveOrigin: {
+        ASSERT(RuntimeEnabledFeatures::cssTransformsUnprefixedEnabled());
+        const AnimatableLengthPoint* animatableLengthPoint = toAnimatableLengthPoint(value);
+        style->setPerspectiveOriginX(animatableValueToLength(animatableLengthPoint->x(), state));
+        style->setPerspectiveOriginY(animatableValueToLength(animatableLengthPoint->y(), state));
+        return;
+    }
     case CSSPropertyWebkitPerspectiveOriginX:
+        ASSERT(!RuntimeEnabledFeatures::cssTransformsUnprefixedEnabled());
         style->setPerspectiveOriginX(animatableValueToLength(value, state));
         return;
     case CSSPropertyWebkitPerspectiveOriginY:
+        ASSERT(!RuntimeEnabledFeatures::cssTransformsUnprefixedEnabled());
         style->setPerspectiveOriginY(animatableValueToLength(value, state));
         return;
     case CSSPropertyShapeOutside: