Move the remaining rendering/svg/RenderSVG* files to layout.

LayoutTests/svg/custom/use-forward-refs-expected.txt

Index: LayoutTests/svg/custom/use-forward-refs-expected.txt
diff --git a/LayoutTests/svg/custom/use-forward-refs-expected.txt b/LayoutTests/svg/custom/use-forward-refs-expected.txt
index 6a22264ac367bd040b4b4c2b918f877e72a93140..6fc9408f5f7ef86b236a663bec191e32098005e6 100644
--- a/LayoutTests/svg/custom/use-forward-refs-expected.txt
+++ b/LayoutTests/svg/custom/use-forward-refs-expected.txt
@@ -1,7 +1,7 @@
 layer at (0,0) size 800x600
   RenderView at (0,0) size 800x600
 layer at (0,0) size 200x200
-  RenderSVGRoot {svg} at (8,8) size 84x74
+  LayoutSVGRoot {svg} at (8,8) size 84x74
     LayoutSVGContainer {use} at (8,8) size 44x54 [transform={m=((1.00,0.00)(0.00,1.00)) t=(-39.84,-20.16)}]
       LayoutSVGPath {path} at (8,8) size 44x54 [stroke={[type=SOLID] [color=#000000] [stroke width=0.33]}] [fill={[type=SOLID] [color=#4C4C4C]}] [data="M 50 50 L 50 80 L 90 60 L 90 30 Z"]
     LayoutSVGContainer {use} at (11,10) size 43x53 [transform={m=((1.00,0.00)(0.00,1.00)) t=(-37.34,-18.59)}]