Implement filter primitive subregion on accelerated reference filters (FEColorMatrix a…

Source/core/platform/graphics/filters/FilterEffect.h

Index: Source/core/platform/graphics/filters/FilterEffect.h
diff --git a/Source/core/platform/graphics/filters/FilterEffect.h b/Source/core/platform/graphics/filters/FilterEffect.h
index 8353bf66ed9ab43840d861948db18d42442e44cc..2aabe06acf48bcf4928b3c87fd4aa43f92d85336 100644
--- a/Source/core/platform/graphics/filters/FilterEffect.h
+++ b/Source/core/platform/graphics/filters/FilterEffect.h
@@ -142,6 +142,7 @@ public:
     void setEffectBoundaries(const FloatRect& effectBoundaries) { m_effectBoundaries = effectBoundaries; }
 
     Filter* filter() { return m_filter; }
+    const Filter* filter() const { return m_filter; }
 
     bool clipsToBounds() const { return m_clipsToBounds; }
     void setClipsToBounds(bool value) { m_clipsToBounds = value; }
@@ -169,6 +170,7 @@ protected:
 
     // If a pre-multiplied image, check every pixel for validity and correct if necessary.
     void forceValidPreMultipliedPixels();
+    SkIRect getCropRect(const FloatSize& cropOffset) const;
 
 private:
     virtual void applySoftware() = 0;