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

LayoutTests/platform/linux/svg/custom/masking-clipping-hidpi-expected.txt

Index: LayoutTests/platform/linux/svg/custom/masking-clipping-hidpi-expected.txt
diff --git a/LayoutTests/platform/linux/svg/custom/masking-clipping-hidpi-expected.txt b/LayoutTests/platform/linux/svg/custom/masking-clipping-hidpi-expected.txt
index ea13660472d74399ea38e46fcaae32931f32c380..6679c81f9d19166c292ce85a41809207161a2cd6 100644
--- a/LayoutTests/platform/linux/svg/custom/masking-clipping-hidpi-expected.txt
+++ b/LayoutTests/platform/linux/svg/custom/masking-clipping-hidpi-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 284x362
-    RenderSVGHiddenContainer {defs} at (0,0) size 0x0
+    LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
       LayoutSVGResourceMasker {mask} [id="textMask"] [maskUnits=objectBoundingBox] [maskContentUnits=userSpaceOnUse]
         LayoutSVGRect {rect} at (0,0) size 800x600 [fill={[type=SOLID] [color=#FFFFFF]}] [x=0.00] [y=0.00] [width=800.00] [height=600.00]
         LayoutSVGText {text} at (0,-2) size 160x18 contains 1 chunk(s)
@@ -11,20 +11,20 @@ layer at (0,0) size 800x600
     LayoutSVGRect {rect} at (0,0) size 200x100 [fill={[type=SOLID] [color=#000000]}] [x=0.00] [y=0.00] [width=200.00] [height=100.00]
     LayoutSVGRect {rect} at (0,0) size 200x100 [fill={[type=SOLID] [color=#FFFFFF]}] [x=0.00] [y=0.00] [width=200.00] [height=100.00]
       [masker="textMask"] LayoutSVGResourceMasker {mask} at (0,-2) size 220x112
-    RenderSVGHiddenContainer {defs} at (0,0) size 0x0
+    LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
       LayoutSVGResourceLinearGradient {linearGradient} [id="blackGradient"] [gradientUnits=objectBoundingBox] [start=(0,0)] [end=(1,0)]
         RenderSVGGradientStop {stop} [offset=0.00] [color=#000000]
         RenderSVGGradientStop {stop} [offset=1.00] [color=#000000]
     LayoutSVGText {text} at (0,22) size 284x18 contains 1 chunk(s)
       LayoutSVGInlineText {#text} at (0,0) size 284x18
         chunk 1 text run 1 at (0.00,36.00) startOffset 0 endOffset 47 width 283.50: "This text and the circles should also be sharp."
-    RenderSVGHiddenContainer {defs} at (0,0) size 0x0
+    LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
       LayoutSVGResourceClipper {clipPath} [id="circleClipPath"] [clipPathUnits=objectBoundingBox]
         LayoutSVGEllipse {circle} at (0,0) size 1x1 [fill={[type=SOLID] [color=#000000]}] [cx=0.25] [cy=0.25] [r=0.20]
         LayoutSVGEllipse {circle} at (0,0) size 1x1 [fill={[type=SOLID] [color=#000000]}] [cx=0.25] [cy=0.75] [r=0.20]
     LayoutSVGRect {rect} at (4,65) size 41x90 [fill={[type=SOLID] [color=#000000]}] [x=0.00] [y=60.00] [width=100.00] [height=100.00]
       [clipPath="circleClipPath"] LayoutSVGResourceClipper {clipPath} at (5,65) size 40x90
-    RenderSVGHiddenContainer {defs} at (0,0) size 0x0
+    LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
       LayoutSVGResourcePattern {pattern} [id="Pattern"] [patternUnits=objectBoundingBox] [patternContentUnits=userSpaceOnUse]
         LayoutSVGEllipse {circle} at (5,5) size 40x40 [fill={[type=LINEAR-GRADIENT] [id="blackGradient"]}] [cx=25.00] [cy=25.00] [r=20.00]
     LayoutSVGRect {rect} at (0,162) size 200x200 [fill={[type=PATTERN] [id="Pattern"]}] [x=0.00] [y=162.00] [width=200.00] [height=200.00]