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

LayoutTests/svg/custom/grayscale-gradient-mask-2-expected.txt

Index: LayoutTests/svg/custom/grayscale-gradient-mask-2-expected.txt
diff --git a/LayoutTests/svg/custom/grayscale-gradient-mask-2-expected.txt b/LayoutTests/svg/custom/grayscale-gradient-mask-2-expected.txt
index f9627bc541c2aa03f6e165973a58b2fd75ca7e9c..890f859b823d0995232ba28ff2517361a813f70b 100644
--- a/LayoutTests/svg/custom/grayscale-gradient-mask-2-expected.txt
+++ b/LayoutTests/svg/custom/grayscale-gradient-mask-2-expected.txt
@@ -1,11 +1,11 @@
 layer at (0,0) size 800x600
   RenderView at (0,0) size 800x600
 layer at (0,0) size 800x600
-  RenderSVGRoot {svg} at (0,143) size 781x294
+  LayoutSVGRoot {svg} at (0,143) size 781x294
     LayoutSVGHiddenContainer {defs} at (0,0) size 0x0
       LayoutSVGResourceLinearGradient {linearGradient} [id="Gradient"] [gradientUnits=userSpaceOnUse] [start=(0,0)] [end=(800,0)]
-        RenderSVGGradientStop {stop} [offset=0.00] [color=#FFFFFF]
-        RenderSVGGradientStop {stop} [offset=1.00] [color=#000000]
+        LayoutSVGGradientStop {stop} [offset=0.00] [color=#FFFFFF]
+        LayoutSVGGradientStop {stop} [offset=1.00] [color=#000000]
     LayoutSVGResourceMasker {mask} [id="Mask1"] [maskUnits=userSpaceOnUse] [maskContentUnits=userSpaceOnUse]
       LayoutSVGRect {rect} at (0,143) size 781x99 [fill={[type=LINEAR-GRADIENT] [id="Gradient"]}] [x=0.00] [y=0.00] [width=800.00] [height=100.00]
     LayoutSVGResourceMasker {mask} [id="Mask2"] [maskUnits=userSpaceOnUse] [maskContentUnits=userSpaceOnUse]