[S.P.] Move clip painting to SVGClipPainter.

Source/core/paint/SVGClipPainter.h

+// 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 SVGClipPainter_h
+#define SVGClipPainter_h
+
+#include "platform/geometry/FloatRect.h"
+#include "platform/graphics/paint/DisplayItem.h"
+
+namespace blink {
+
+class AffineTransform;
+class GraphicsContext;
+class LayoutObject;
+class LayoutSVGResourceClipper;
+
+class SVGClipPainter {
+public:
+    enum ClipperState {
+        ClipperNotApplied,
+        ClipperAppliedPath,
+        ClipperAppliedMask
+    };
+
+    SVGClipPainter(LayoutSVGResourceClipper& clip) : m_clip(clip) { }
+
+    // FIXME: Filters are also stateful resources that could benefit from having their state managed
+    //        on the caller stack instead of the current hashmap. We should look at refactoring these
+    //        into a general interface that can be shared.
+    bool applyStatefulResource(LayoutObject*, GraphicsContext*&, ClipperState&);

[pdr., 2015/03/05 22:21:16]

Not your fault but can you switch these pointer references to be just references
(or pointers, if needed)? (i.e., GraphicsContext*& -> GraphicsContext&)

[Erik Dahlström (inactive), 2015/03/06 11:55:50]

Made them pointers for now.

+    void postApplyStatefulResource(LayoutObject*, GraphicsContext*&, ClipperState&);
+
+    // clipPath can be clipped too, but don't have a boundingBox or paintInvalidationRect. So we can't call
+    // applyResource directly and use the rects from the object, since they are empty for LayoutSVGResources
+    // FIXME: We made applyClippingToContext public because we cannot call applyResource on HTML elements (it asserts on LayoutObject::objectBoundingBox)
+    bool applyClippingToContext(LayoutObject*, const FloatRect&, const FloatRect&, GraphicsContext*, ClipperState&);
+
+private:
+    void drawClipMaskContent(GraphicsContext*, DisplayItemClient, const FloatRect&);
+
+    LayoutSVGResourceClipper& m_clip;
+};
+
+} // namespace blink
+
+#endif // SVGShapePainter_h