[S.P.] Move filter painting to SVGFilterPainter.

Source/core/paint/SVGFilterPainter.h

Index: Source/core/paint/SVGFilterPainter.h
diff --git a/Source/core/paint/SVGFilterPainter.h b/Source/core/paint/SVGFilterPainter.h
new file mode 100644
index 0000000000000000000000000000000000000000..0e7dc0d02d55b661bcc0ce5582797f5ae4acbe93
--- /dev/null
+++ b/Source/core/paint/SVGFilterPainter.h
@@ -0,0 +1,29 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SVGFilterPainter_h
+#define SVGFilterPainter_h
+
+namespace blink {
+
+class GraphicsContext;
+class LayoutObject;
+class LayoutSVGResourceFilter;
+
+class SVGFilterPainter {
+public:
+    SVGFilterPainter(LayoutSVGResourceFilter& filter) : m_filter(filter) { }
+
+    // Returns the context that should be used to paint the filter contents, or
+    // null if the content should not be recorded.
+    GraphicsContext* prepareEffect(LayoutObject*, GraphicsContext*);
+    void finishEffect(LayoutObject*, GraphicsContext*);
+
+private:
+    LayoutSVGResourceFilter& m_filter;
+};
+
+} // namespace blink
+
+#endif // SVGFilterPainter_h