Derive the SourceAlpha filter input from SourceGraphic

Source/core/svg/graphics/filters/SVGFilterBuilder.h

 /*
  * Copyright (C) 2008 Alex Mathews <possessedpenguinbob@gmail.com>
  * Copyright (C) 2009 Dirk Schulze <krit@webkit.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 19 matching lines @@
 #include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class LayoutObject;
 
 class SVGFilterBuilder final : public RefCountedWillBeGarbageCollectedFinalized<SVGFilterBuilder> {
 public:
     typedef WillBeHeapHashSet<RawPtrWillBeMember<FilterEffect>> FilterEffectSet;
 
-    static PassRefPtrWillBeRawPtr<SVGFilterBuilder> create(PassRefPtrWillBeRawPtr<FilterEffect> sourceGraphic, PassRefPtrWillBeRawPtr<FilterEffect> sourceAlpha)
+    static PassRefPtrWillBeRawPtr<SVGFilterBuilder> create(PassRefPtrWillBeRawPtr<FilterEffect> sourceGraphic)
     {
-        return adoptRefWillBeNoop(new SVGFilterBuilder(sourceGraphic, sourceAlpha));
+        return adoptRefWillBeNoop(new SVGFilterBuilder(sourceGraphic));
     }
 
     void add(const AtomicString& id, PassRefPtrWillBeRawPtr<FilterEffect>);
 
     FilterEffect* getEffectById(const AtomicString& id) const;
     FilterEffect* lastEffect() const { return m_lastEffect.get(); }
 
     void appendEffectToEffectReferences(PassRefPtrWillBeRawPtr<FilterEffect>, LayoutObject*);
 
     inline FilterEffectSet& effectReferences(FilterEffect* effect)
     {
         // Only allowed for effects belongs to this builder.
         ASSERT(m_effectReferences.contains(effect));
         return m_effectReferences.find(effect)->value;
     }
 
     // Required to change the attributes of a filter during an svgAttributeChanged.
     inline FilterEffect* effectByRenderer(LayoutObject* object) { return m_effectRenderer.get(object); }
 
     void clearEffects();
     void clearResultsRecursive(FilterEffect*);
 
     DECLARE_TRACE();
 
 private:
-    SVGFilterBuilder(PassRefPtrWillBeRawPtr<FilterEffect> sourceGraphic, PassRefPtrWillBeRawPtr<FilterEffect> sourceAlpha);
+    SVGFilterBuilder(PassRefPtrWillBeRawPtr<FilterEffect> sourceGraphic);
 
     inline void addBuiltinEffects()
     {
         for (const auto& entry : m_builtinEffects)
             m_effectReferences.add(entry.value, FilterEffectSet());
     }
 
     typedef WillBeHeapHashMap<AtomicString, RefPtrWillBeMember<FilterEffect>> NamedFilterEffectMap;
 
     NamedFilterEffectMap m_builtinEffects;
     NamedFilterEffectMap m_namedEffects;
     // The value is a list, which contains those filter effects,
     // which depends on the key filter effect.
     WillBeHeapHashMap<RefPtrWillBeMember<FilterEffect>, FilterEffectSet> m_effectReferences;
     WillBeHeapHashMap<LayoutObject*, RawPtrWillBeMember<FilterEffect>> m_effectRenderer;
 
     RefPtrWillBeMember<FilterEffect> m_lastEffect;
 };
 
 } // namespace blink
 
 #endif // SVGFilterBuilder_h