Pixel snap SVG's root border box to local transform [spv2]

third_party/WebKit/Source/core/paint/SVGRootPainter.h

Index: third_party/WebKit/Source/core/paint/SVGRootPainter.h
diff --git a/third_party/WebKit/Source/core/paint/SVGRootPainter.h b/third_party/WebKit/Source/core/paint/SVGRootPainter.h
index 0c8f74f61c2b7de418dfd785c07ca2d0876b5683..b11acdd0934fb64640fbdb0ac9a08d33c2bbc3dc 100644
--- a/third_party/WebKit/Source/core/paint/SVGRootPainter.h
+++ b/third_party/WebKit/Source/core/paint/SVGRootPainter.h
@@ -10,6 +10,8 @@
 namespace blink {
 
 struct PaintInfo;
+class AffineTransform;
+class IntRect;
 class LayoutPoint;
 class LayoutSVGRoot;
 
@@ -20,7 +22,14 @@ public:
 
     void paint(const PaintInfo&, const LayoutPoint&);
 
+    // The embedded SVG document uses an unsnapped viewport box for layout, while SVG root's border
+    // box ultimately gets snapped during paint. This translate/scale transform is applied to
+    // compensate the difference, in addition to applying the local to border box transform.
+    AffineTransform transformToPixelSnappedBorderBox(const LayoutPoint& paintOffset) const;
+
 private:
+    IntRect pixelSnappedSize(const LayoutPoint& paintOffset) const;
+
     const LayoutSVGRoot& m_layoutSVGRoot;
 };