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

LayoutTests/svg/filters/innershadow-expected.txt

Index: LayoutTests/svg/filters/innershadow-expected.txt
diff --git a/LayoutTests/svg/filters/innershadow-expected.txt b/LayoutTests/svg/filters/innershadow-expected.txt
index 4ee6319ed5d30497efc80ec81ea38092c07071d7..6282cec2b88201909198483e63248a53045c5369 100644
--- a/LayoutTests/svg/filters/innershadow-expected.txt
+++ b/LayoutTests/svg/filters/innershadow-expected.txt
@@ -18,7 +18,7 @@ layer at (0,0) size 800x400
         LayoutSVGContainer {g} at (480,100) size 200x200
           LayoutSVGRect {rect} at (480,100) size 200x200 [fill={[type=SOLID] [color=#FF0000]}] [x=0.00] [y=-100.00] [width=100.00] [height=100.00]
           LayoutSVGRect {rect} at (494,114) size 186x186 [fill={[type=SOLID] [color=#008000]}] [x=7.00] [y=-93.00] [width=93.00] [height=93.00]
-    RenderSVGHiddenContainer {defs} at (0,0) size 0x0
+    LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
       LayoutSVGContainer {g} at (0,0) size 0x0
         LayoutSVGRect {rect} at (0,0) size 0x0 [fill={[type=SOLID] [color=#FF0000]}] [x=0.00] [y=-100.00] [width=100.00] [height=100.00]
         LayoutSVGRect {rect} at (0,0) size 0x0 [fill={[type=SOLID] [color=#008000]}] [x=7.00] [y=-93.00] [width=93.00] [height=93.00]