Add a runtime flag for distributing extra logical height to rowspans

LayoutTests/platform/linux/tables/mozilla/core/bloomberg-expected.txt

Index: LayoutTests/platform/linux/tables/mozilla/core/bloomberg-expected.txt
diff --git a/LayoutTests/platform/linux/tables/mozilla/core/bloomberg-expected.txt b/LayoutTests/platform/linux/tables/mozilla/core/bloomberg-expected.txt
index c01cd392484653b71905e3f39d08784e1bbb7b10..49f471bceb76da60913d55095fb465f5ddaebad9 100644
--- a/LayoutTests/platform/linux/tables/mozilla/core/bloomberg-expected.txt
+++ b/LayoutTests/platform/linux/tables/mozilla/core/bloomberg-expected.txt
@@ -5,7 +5,7 @@ layer at (0,0) size 785x716
     RenderBody {BODY} at (8,8) size 769x692 [color=#333333] [bgcolor=#FFFFFF]
       RenderTable {TABLE} at (0,0) size 636x663 [border: (1px outset #808080)]
         RenderTableSection {TBODY} at (1,1) size 634x661
-          RenderTableRow {TR} at (0,0) size 634x28
+          RenderTableRow {TR} at (0,0) size 634x24
             RenderTableCell {TD} at (0,0) size 148x661 [bgcolor=#660000] [border: (1px inset #808080)] [r=0 c=0 rs=6 cs=1]
               RenderInline {B} at (0,0) size 63x19
                 RenderInline {A} at (0,0) size 63x19
@@ -214,22 +214,22 @@ layer at (0,0) size 785x716
               RenderBR {BR} at (4,637) size 0x19
             RenderTableCell {TD} at (148,0) size 486x24 [bgcolor=#660000] [border: (1px inset #808080)] [r=0 c=1 rs=1 cs=3]
               RenderImage {IMG} at (10,4) size 466x16
-          RenderTableRow {TR} at (0,28) size 634x82
-            RenderTableCell {TD} at (148,28) size 128x69 [border: (1px inset #808080)] [r=1 c=1 rs=1 cs=1]
+          RenderTableRow {TR} at (0,24) size 634x69
+            RenderTableCell {TD} at (148,24) size 128x69 [border: (1px inset #808080)] [r=1 c=1 rs=1 cs=1]
               RenderInline {A} at (0,0) size 120x19
                 RenderText {#text} at (0,0) size 0x0
                 RenderImage {IMG} at (4,4) size 120x60
               RenderText {#text} at (0,0) size 0x0
               RenderText {#text} at (0,0) size 0x0
               RenderImage {IMG} at (4,64) size 120x1
-            RenderTableCell {TD} at (276,28) size 175x69 [border: (1px inset #808080)] [r=1 c=2 rs=1 cs=1]
+            RenderTableCell {TD} at (276,24) size 175x69 [border: (1px inset #808080)] [r=1 c=2 rs=1 cs=1]
               RenderInline {A} at (0,0) size 167x19
                 RenderText {#text} at (0,0) size 0x0
                 RenderImage {IMG} at (4,4) size 167x60
               RenderText {#text} at (0,0) size 0x0
               RenderText {#text} at (0,0) size 0x0
               RenderImage {IMG} at (4,64) size 167x1
-            RenderTableCell {TD} at (451,28) size 183x531 [bgcolor=#CCCC99] [border: (1px inset #808080)] [r=1 c=3 rs=6 cs=1]
+            RenderTableCell {TD} at (451,24) size 183x531 [bgcolor=#CCCC99] [border: (1px inset #808080)] [r=1 c=3 rs=6 cs=1]
               RenderBlock (anonymous) at (4,4) size 175x29
                 RenderInline {FONT} at (0,0) size 147x12
                   RenderInline {FONT} at (0,0) size 147x13
@@ -282,8 +282,8 @@ layer at (0,0) size 785x716
                   RenderImage {IMG} at (25,369) size 125x125
                 RenderText {#text} at (0,0) size 0x0
                 RenderText {#text} at (0,0) size 0x0
-          RenderTableRow {TR} at (0,110) size 634x153
-            RenderTableCell {TD} at (148,110) size 303x128 [bgcolor=#FFFFFF] [border: (1px inset #808080)] [r=2 c=1 rs=1 cs=2]
+          RenderTableRow {TR} at (0,93) size 634x128
+            RenderTableCell {TD} at (148,93) size 303x128 [bgcolor=#FFFFFF] [border: (1px inset #808080)] [r=2 c=1 rs=1 cs=2]
               RenderInline {A} at (0,0) size 0x0
                 RenderImage {IMG} at (4,4) size 288x26
               RenderBR {BR} at (295,4) size 0x19
@@ -300,8 +300,8 @@ layer at (0,0) size 785x716
                   RenderText {#text} at (4,104) size 46x19
                     text run at (4,104) width 46: "More..."
               RenderText {#text} at (0,0) size 0x0
-          RenderTableRow {TR} at (0,263) size 634x396
-            RenderTableCell {TD} at (148,263) size 303x331 [bgcolor=#C0C0C0] [border: (1px inset #808080)] [r=3 c=1 rs=1 cs=2]
+          RenderTableRow {TR} at (0,221) size 634x331
+            RenderTableCell {TD} at (148,221) size 303x331 [bgcolor=#C0C0C0] [border: (1px inset #808080)] [r=3 c=1 rs=1 cs=2]
               RenderImage {IMG} at (4,4) size 290x35
               RenderBR {BR} at (294,39) size 0x0
               RenderInline {A} at (0,0) size 248x19