blink: Add backdrop-filter support

Source/core/css/ComputedStyleCSSValueMapping.h

Index: Source/core/css/ComputedStyleCSSValueMapping.h
diff --git a/Source/core/css/ComputedStyleCSSValueMapping.h b/Source/core/css/ComputedStyleCSSValueMapping.h
index 76764c17212b5558688ae3c2257b97e7ed2de3f2..d18a6c27ec833062cf1e9a20d99cd960998bc243 100644
--- a/Source/core/css/ComputedStyleCSSValueMapping.h
+++ b/Source/core/css/ComputedStyleCSSValueMapping.h
@@ -13,6 +13,7 @@ namespace blink {
 class CSSPrimitiveValue;
 class LayoutObject;
 class ComputedStyle;
+class FilterOperations;
 class ShadowData;
 class ShadowList;
 class StyleColor;
@@ -26,7 +27,7 @@ private:
     static PassRefPtrWillBeRawPtr<CSSPrimitiveValue> currentColorOrValidColor(const ComputedStyle&, const StyleColor&);
     static PassRefPtrWillBeRawPtr<CSSValue> valueForShadowData(const ShadowData&, const ComputedStyle&, bool useSpread);
     static PassRefPtrWillBeRawPtr<CSSValue> valueForShadowList(const ShadowList*, const ComputedStyle&, bool useSpread);
-    static PassRefPtrWillBeRawPtr<CSSValue> valueForFilter(const ComputedStyle&);
+    static PassRefPtrWillBeRawPtr<CSSValue> valueForFilter(const ComputedStyle&, const FilterOperations&);
     static PassRefPtrWillBeRawPtr<CSSValue> valueForFont(const ComputedStyle&);
 };