Implement -webkit-box-reflect as a filter.

third_party/WebKit/Source/core/layout/LayoutObject.h

Index: third_party/WebKit/Source/core/layout/LayoutObject.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.h b/third_party/WebKit/Source/core/layout/LayoutObject.h
index 9a833b488ea0c1837e14b31b9a1f301865e6d40d..67503343f4d4f9c05e7ac004f6fd5f101c1a8173 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.h
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.h
@@ -717,10 +717,15 @@ public:
     bool hasMask() const { return style() && style()->hasMask(); }
     bool hasClipPath() const { return style() && style()->clipPath(); }
     bool hasHiddenBackface() const { return style() && style()->backfaceVisibility() == BackfaceVisibilityHidden; }
-
-    bool hasFilter() const { return style() && style()->hasFilter(); }
     bool hasBackdropFilter() const { return style() && style()->hasBackdropFilter(); }
 
+    // Returns |true| if any property that renders using filter operations is
+    // used (including, but not limited to, 'filter').
+    bool hasFilterInducingProperty() const
+    {
+        return (style() && style()->hasFilter()) || (RuntimeEnabledFeatures::cssBoxReflectFilterEnabled() && hasReflection());
+    }
+
     bool hasShapeOutside() const { return style() && style()->shapeOutside(); }
 
     inline bool preservesNewline() const;
@@ -1267,7 +1272,7 @@ public:
     bool shouldUseTransformFromContainer(const LayoutObject* container) const;
     void getTransformFromContainer(const LayoutObject* container, const LayoutSize& offsetInContainer, TransformationMatrix&) const;
 
-    bool createsGroup() const { return isTransparent() || hasMask() || hasFilter() || style()->hasBlendMode(); }
+    bool createsGroup() const { return isTransparent() || hasMask() || hasFilterInducingProperty() || style()->hasBlendMode(); }
 
     // Collects rectangles that the outline of this object would be drawing along the outside of,
     // even if the object isn't styled with a outline for now. The rects also cover continuations.