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

LayoutTests/svg/W3C-SVG-1.1-SE/svgdom-over-01-f-expected.txt

 layer at (0,0) size 480x360
   RenderView at (0,0) size 480x360
 layer at (0,0) size 480x360
   RenderSVGRoot {svg} at (0,0) size 480x360
-    RenderSVGHiddenContainer {defs} at (0,0) size 0x0
+    LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
     LayoutSVGContainer {g} at (10,49) size 410x230
-      RenderSVGHiddenContainer {defs} at (0,0) size 0x0
+      LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
         LayoutSVGRect {rect} at (0,0) size 1x1 [fill={[type=SOLID] [color=#000000]}] [x=0.00] [y=0.00] [width=1.00] [height=1.00]
         RenderSVGGradientStop {stop} [offset=0.00] [color=#000000]
         LayoutSVGImage {image} at (0,0) size 1x1
         LayoutSVGResourceRadialGradient {radialGradient} [id="g"] [gradientUnits=objectBoundingBox] [center=(0.50,0.50)] [focal=(0.50,0.50)] [radius=0.50] [focalRadius=0.00]
         LayoutSVGText {text}
         LayoutSVGText {text} at (0,-15) size 73x19 contains 1 chunk(s)
           LayoutSVGInlineText {#text} at (0,0) size 73x18
             chunk 1 text run 1 at (0.00,0.00) startOffset 0 endOffset 4 width 44.01: "some"
             chunk 1 text run 2 at (43.83,0.00) startOffset 4 endOffset 5 width 5.00: "t"
             chunk 1 text run 3 at (48.58,0.00) startOffset 5 endOffset 6 width 10.01: "e"
             chunk 1 text run 4 at (58.10,0.00) startOffset 6 endOffset 8 width 14.00: "xt"
         LayoutSVGResourceMarker {marker} [id="m"] [markerUnits=strokeWidth] [ref at (0,0)] [angle=0.00]
-        RenderSVGViewportContainer {svg} at (0,0) size 0x0
+        LayoutSVGViewportContainer {svg} at (0,0) size 0x0
         LayoutSVGResourceFilter {filter} [id="f"] [filterUnits=objectBoundingBox] [primitiveUnits=userSpaceOnUse]
         LayoutSVGPath {polygon} at (0,0) size 0x0 [fill={[type=SOLID] [color=#000000]}] [points=""]
       LayoutSVGContainer {g} at (10,49) size 140x10 [transform={m=((1.00,0.00)(0.00,1.00)) t=(10.00,50.00)}]
         LayoutSVGRect {rect} at (10,51) size 5x5 [fill={[type=SOLID] [color=#00FF00]}] [x=0.00] [y=1.00] [width=5.00] [height=5.00]
         LayoutSVGText {text} at (10,-1) size 130x10 contains 1 chunk(s)
           LayoutSVGInlineText {#text} at (0,0) size 130x9
             chunk 1 text run 1 at (10.00,7.00) startOffset 0 endOffset 1 width 3.00: "r"
             chunk 1 text run 2 at (12.38,7.00) startOffset 1 endOffset 9 width 35.02: ".x.baseV"
             chunk 1 text run 3 at (46.86,7.00) startOffset 9 endOffset 13 width 14.00: "al.v"
             chunk 1 text run 4 at (60.71,7.00) startOffset 13 endOffset 25 width 48.54: "alue == 0: P"
@@ skipping 264 matching lines @@
           chunk 1 text run 1 at (10.00,340.00) startOffset 0 endOffset 2 width 40.90: "$R"
           chunk 1 text run 2 at (50.51,340.00) startOffset 2 endOffset 3 width 17.79: "e"
           chunk 1 text run 3 at (67.82,340.00) startOffset 3 endOffset 12 width 117.38: "vision: 1"
           chunk 1 text run 4 at (182.83,340.00) startOffset 12 endOffset 16 width 53.38: ".9 $"
     LayoutSVGRect {rect} at (0,0) size 480x360 [stroke={[type=SOLID] [color=#000000]}] [x=1.00] [y=1.00] [width=478.00] [height=358.00]
     LayoutSVGContainer {g} at (0,0) size 480x23
       LayoutSVGRect {rect} at (0,0) size 480x22 [stroke={[type=SOLID] [color=#000000]}] [fill={[type=SOLID] [color=#FF0000]}] [x=1.00] [y=1.00] [width=478.00] [height=20.00]
       LayoutSVGText {text} at (206,2) size 68x20 contains 1 chunk(s)
         LayoutSVGInlineText {#text} at (0,0) size 67x20
           chunk 1 (middle anchor) text run 1 at (206.67,18.00) startOffset 0 endOffset 5 width 66.66: "DRAFT"