Fix getBBox() returning (0,0) bug when width or height is zero

LayoutTests/platform/linux/svg/clip-path/deep-nested-clip-in-mask-different-unitTypes-expected.txt

Index: LayoutTests/platform/linux/svg/clip-path/deep-nested-clip-in-mask-different-unitTypes-expected.txt
diff --git a/LayoutTests/platform/win/svg/clip-path/deep-nested-clip-in-mask-different-unitTypes-expected.txt b/LayoutTests/platform/linux/svg/clip-path/deep-nested-clip-in-mask-different-unitTypes-expected.txt
similarity index 94%
copy from LayoutTests/platform/win/svg/clip-path/deep-nested-clip-in-mask-different-unitTypes-expected.txt
copy to LayoutTests/platform/linux/svg/clip-path/deep-nested-clip-in-mask-different-unitTypes-expected.txt
index 0a76635216ccde3522dd39b7e742c2eb5b9441b4..9e4132d4a918145954aa0d0208288ab2b8cc4537 100644
--- a/LayoutTests/platform/win/svg/clip-path/deep-nested-clip-in-mask-different-unitTypes-expected.txt
+++ b/LayoutTests/platform/linux/svg/clip-path/deep-nested-clip-in-mask-different-unitTypes-expected.txt
@@ -4,19 +4,19 @@ layer at (0,0) size 800x600
   RenderSVGRoot {svg} at (0,0) size 226x229
     RenderSVGHiddenContainer {defs} at (0,0) size 0x0
       RenderSVGResourceClipper {clipPath} [id="clip0"] [clipPathUnits=userSpaceOnUse]
-        RenderSVGEllipse {circle} at (50,50) size 100x100 [fill={[type=SOLID] [color=#000000]}] [cx=100.00] [cy=100.00] [r=50.00]
+        RenderSVGEllipse {circle} at (49,49) size 102x102 [fill={[type=SOLID] [color=#000000]}] [cx=100.00] [cy=100.00] [r=50.00]
       RenderSVGResourceClipper {clipPath} [id="clip1"] [clipPathUnits=objectBoundingBox]
         RenderSVGEllipse {circle} at (0,0) size 1x1 [fill={[type=SOLID] [color=#000000]}] [cx=0.00] [cy=0.00] [r=0.50]
         RenderSVGEllipse {circle} at (0,0) size 1x2 [fill={[type=SOLID] [color=#000000]}] [cx=0.00] [cy=1.00] [r=0.50]
       RenderSVGResourceClipper {clipPath} [id="clip2"] [clipPathUnits=userSpaceOnUse]
         RenderSVGEllipse {circle} at (0,0) size 2x1 [transform={m=((0.01,0.00)(0.00,0.01)) t=(0.00,0.00)}] [fill={[type=SOLID] [color=#000000]}] [cx=100.00] [cy=0.00] [r=50.00]
         RenderSVGRect {rect} at (0,0) size 2x2 [transform={m=((0.01,0.00)(0.00,0.01)) t=(0.00,0.00)}] [fill={[type=SOLID] [color=#000000]}] [x=0.00] [y=0.00] [width=100.00] [height=100.00]
-          [clipPath="clip0"] RenderSVGResourceClipper {clipPath} at (50,50) size 100x100
+          [clipPath="clip0"] RenderSVGResourceClipper {clipPath} at (49.50,49.50) size 101x101
       RenderSVGResourceClipper {clipPath} [id="clip"] [clipPathUnits=objectBoundingBox]
         RenderSVGRect {rect} at (0,0) size 1x1 [fill={[type=SOLID] [color=#000000]}] [x=0.00] [y=0.00] [width=1.00] [height=1.00]
-          [clipPath="clip1"] RenderSVGResourceClipper {clipPath} at (-0.50,-0.50) size 1x2
+          [clipPath="clip1"] RenderSVGResourceClipper {clipPath} at (-1,-1) size 2x3
         RenderSVGRect {rect} at (0,0) size 1x1 [fill={[type=SOLID] [color=#000000]}] [x=0.00] [y=0.00] [width=1.00] [height=1.00]
-          [clipPath="clip2"] RenderSVGResourceClipper {clipPath} at (0.50,-0.50) size 1.00x1.50
+          [clipPath="clip2"] RenderSVGResourceClipper {clipPath} at (0.50,-0.51) size 1.01x1.51
       RenderSVGResourceMasker {mask} [id="mask1"] [maskUnits=objectBoundingBox] [maskContentUnits=objectBoundingBox]
         RenderSVGRect {rect} at (0,0) size 1x1 [fill={[type=SOLID] [color=#FFFFFF]}] [x=0.00] [y=0.00] [width=1.00] [height=1.00]
         RenderSVGRect {rect} at (0,0) size 1x1 [fill={[type=SOLID] [color=#000000]}] [x=0.00] [y=0.00] [width=1.00] [height=1.00]