Fix layoutOverflowRect in case of explicit 'overflow: scroll', but no overflow content

LayoutTests/platform/win/fast/block/float/028-expected.txt

Index: LayoutTests/platform/win/fast/block/float/028-expected.txt
diff --git a/LayoutTests/platform/win/fast/block/float/028-expected.txt b/LayoutTests/platform/win/fast/block/float/028-expected.txt
index 837e24cfe67f4e85c8efe8ed5e3892ac76f0cede..8829abdf7ea23e02f07e3fa28c7d0fad4220165b 100644
--- a/LayoutTests/platform/win/fast/block/float/028-expected.txt
+++ b/LayoutTests/platform/win/fast/block/float/028-expected.txt
@@ -38,14 +38,14 @@ layer at (0,0) size 785x1432
         RenderImage {IMG} at (184.50,0) size 384.50x50 [bgcolor=#008000]
 layer at (8,208) size 569x59 clip at (25,210) size 550x40
   RenderBlock {DIV} at (0,0) size 569x59 [border: (2px solid #0000FF)]
-    RenderText {#text} at (39,2) size 513x39
-      text run at (39,2) width 513: "This is an overflow:scroll region. It should sit on the same line as the float and wrap as"
-      text run at (290,22) width 4 RTL: "."
-      text run at (294,22) width 258: "needed to fit within the remaining line width"
-layer at (189,816) size 388x79 clip at (206,818) size 369x60 scrollX 13 scrollWidth 383
+    RenderText {#text} at (54,2) size 513x39
+      text run at (54,2) width 513: "This is an overflow:scroll region. It should sit on the same line as the float and wrap as"
+      text run at (305,22) width 4 RTL: "."
+      text run at (309,22) width 258: "needed to fit within the remaining line width"
+layer at (189,816) size 388x79 clip at (206,818) size 369x60
   RenderBlock {DIV} at (180.50,0) size 388.50x79 [border: (2px solid #0000FF)]
-    RenderText {#text} at (5,2) size 368x59
-      text run at (5,2) width 366: "This is an overflow:scroll region. It should sit on the same line"
-      text run at (3,22) width 368: "as the float and wrap as needed to fit within the remaining line"
-      text run at (334,42) width 4 RTL: "."
-      text run at (338,42) width 33: "width"
+    RenderText {#text} at (20,2) size 368x59
+      text run at (20,2) width 366: "This is an overflow:scroll region. It should sit on the same line"
+      text run at (18,22) width 368: "as the float and wrap as needed to fit within the remaining line"
+      text run at (349,42) width 4 RTL: "."
+      text run at (353,42) width 33: "width"