Simplify RenderLayer's handling of filters.

sky/engine/core/css/resolver/FilterOperationResolver.cpp

Index: sky/engine/core/css/resolver/FilterOperationResolver.cpp
diff --git a/sky/engine/core/css/resolver/FilterOperationResolver.cpp b/sky/engine/core/css/resolver/FilterOperationResolver.cpp
index 61fd11a416c2e06454ad1c06e76476f7f364bbc7..9d997606cac86c54c15ce43ba3432bc93bec32fe 100644
--- a/sky/engine/core/css/resolver/FilterOperationResolver.cpp
+++ b/sky/engine/core/css/resolver/FilterOperationResolver.cpp
@@ -40,8 +40,6 @@ namespace blink {
 static FilterOperation::OperationType filterOperationForType(CSSFilterValue::FilterOperationType type)
 {
     switch (type) {
-    case CSSFilterValue::ReferenceFilterOperation:
-        return FilterOperation::REFERENCE;
     case CSSFilterValue::GrayscaleFilterOperation:
         return FilterOperation::GRAYSCALE;
     case CSSFilterValue::SepiaFilterOperation:
@@ -93,9 +91,6 @@ bool FilterOperationResolver::createFilterOperations(CSSValue* inValue, const CS
         CSSFilterValue* filterValue = toCSSFilterValue(i.value());
         FilterOperation::OperationType operationType = filterOperationForType(filterValue->operationType());
 
-        if (operationType == FilterOperation::REFERENCE)
-            continue;
-
         // Check that all parameters are primitive values, with the
         // exception of drop shadow which has a CSSShadowValue parameter.
         if (operationType != FilterOperation::DROP_SHADOW) {