Move the SVG container code from rendering/svg to layout/svg.

LayoutTests/platform/win/svg/custom/recursive-pattern-expected.txt

Index: LayoutTests/platform/win/svg/custom/recursive-pattern-expected.txt
diff --git a/LayoutTests/platform/win/svg/custom/recursive-pattern-expected.txt b/LayoutTests/platform/win/svg/custom/recursive-pattern-expected.txt
index b996346713f9ef3360363f4f8390646b8f2205c7..8feb71ad375e03f8c90d3cb276bebff51381dc65 100644
--- a/LayoutTests/platform/win/svg/custom/recursive-pattern-expected.txt
+++ b/LayoutTests/platform/win/svg/custom/recursive-pattern-expected.txt
@@ -2,7 +2,7 @@ layer at (0,0) size 800x600
   RenderView at (0,0) size 800x600
 layer at (0,0) size 800x600
   RenderSVGRoot {svg} at (0,0) size 650x353
-    RenderSVGHiddenContainer {defs} at (0,0) size 0x0
+    LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
       LayoutSVGResourcePattern {pattern} [id="pattern0"] [patternUnits=userSpaceOnUse] [patternContentUnits=userSpaceOnUse]
         LayoutSVGRect {rect} at (0,0) size 50x50 [fill={[type=SOLID] [color=#000000]}] [x=0.00] [y=0.00] [width=50.00] [height=50.00]
         LayoutSVGRect {rect} at (50,50) size 100x100 [fill={[type=SOLID] [color=#008000]}] [x=50.00] [y=50.00] [width=100.00] [height=100.00]