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

LayoutTests/platform/linux/svg/filters/filter-clip-expected.txt

Index: LayoutTests/platform/linux/svg/filters/filter-clip-expected.txt
diff --git a/LayoutTests/svg/filters/filter-clip-expected.txt b/LayoutTests/platform/linux/svg/filters/filter-clip-expected.txt
similarity index 80%
copy from LayoutTests/svg/filters/filter-clip-expected.txt
copy to LayoutTests/platform/linux/svg/filters/filter-clip-expected.txt
index 4fe9e2d84c33bfd0d4ecd445b14338f51da0d01b..af8c40fef526a44e172272923a9a601aa2b7a089 100644
--- a/LayoutTests/svg/filters/filter-clip-expected.txt
+++ b/LayoutTests/platform/linux/svg/filters/filter-clip-expected.txt
@@ -1,17 +1,17 @@
 layer at (0,0) size 800x600
   RenderView at (0,0) size 800x600
 layer at (0,0) size 800x600
-  RenderSVGRoot {svg} at (20,20) size 100x100
+  RenderSVGRoot {svg} at (19,19) size 102x102
     RenderSVGHiddenContainer {defs} at (0,0) size 0x0
       RenderSVGResourceMasker {mask} [id="mask"] [maskUnits=objectBoundingBox] [maskContentUnits=userSpaceOnUse]
         RenderSVGRect {rect} at (0,0) size 140x140 [fill={[type=SOLID] [color=#008000]}] [x=0.00] [y=0.00] [width=140.00] [height=140.00]
-        RenderSVGEllipse {circle} at (30,30) size 80x80 [fill={[type=SOLID] [color=#FFFF00]}] [cx=70.00] [cy=70.00] [r=40.00]
+        RenderSVGEllipse {circle} at (29,29) size 82x82 [fill={[type=SOLID] [color=#FFFF00]}] [cx=70.00] [cy=70.00] [r=40.00]
       RenderSVGResourceFilter {filter} [id="blur"] [filterUnits=objectBoundingBox] [primitiveUnits=userSpaceOnUse]
         [feGaussianBlur stdDeviation="10.00, 10.00"]
           [SourceGraphic]
       RenderSVGResourceClipper {clipPath} [id="clip"] [clipPathUnits=userSpaceOnUse]
-        RenderSVGEllipse {circle} at (20,20) size 100x100 [fill={[type=SOLID] [color=#000000]}] [cx=70.00] [cy=70.00] [r=50.00]
-    RenderSVGRect {rect} at (20,20) size 100x100 [fill={[type=SOLID] [color=#008000]}] [x=20.00] [y=20.00] [width=100.00] [height=100.00]
+        RenderSVGEllipse {circle} at (19,19) size 102x102 [fill={[type=SOLID] [color=#000000]}] [cx=70.00] [cy=70.00] [r=50.00]
+    RenderSVGRect {rect} at (19,19) size 102x102 [fill={[type=SOLID] [color=#008000]}] [x=20.00] [y=20.00] [width=100.00] [height=100.00]
       [masker="mask"] RenderSVGResourceMasker {mask} at (10,10) size 120x120
-      [clipPath="clip"] RenderSVGResourceClipper {clipPath} at (20,20) size 100x100
+      [clipPath="clip"] RenderSVGResourceClipper {clipPath} at (19.50,19.50) size 101x101
       [filter="blur"] RenderSVGResourceFilter {filter} at (0,0) size 140x140