Move and rename RenderBR to LayoutBR.

LayoutTests/platform/mac/tables/mozilla/bugs/bug23235-expected.txt

Index: LayoutTests/platform/mac/tables/mozilla/bugs/bug23235-expected.txt
diff --git a/LayoutTests/platform/mac/tables/mozilla/bugs/bug23235-expected.txt b/LayoutTests/platform/mac/tables/mozilla/bugs/bug23235-expected.txt
index 8ad73fbf4848e6847d5d1ea5384cd8b68d2615d1..4ec44521e66da0de9c29b07aa028637cb4bc4455 100644
--- a/LayoutTests/platform/mac/tables/mozilla/bugs/bug23235-expected.txt
+++ b/LayoutTests/platform/mac/tables/mozilla/bugs/bug23235-expected.txt
@@ -27,7 +27,7 @@ layer at (0,0) size 800x600
                   LayoutTableRow {TR} at (0,2) size 128x49
                     LayoutTableCell {TD} at (2,2) size 124x49 [border: (1px inset #808080)] [r=0 c=0 rs=1 cs=1]
                       LayoutImage {IMG} at (3,3) size 118x25
-                      RenderBR {BR} at (121,28) size 0x0
+                      LayoutBR {BR} at (121,28) size 0x0
                       RenderText {#text} at (24,28) size 6x18
                         text run at (24,28) width 6: "["
                       RenderInline {I} at (0,0) size 66x18
@@ -58,7 +58,7 @@ layer at (0,0) size 800x600
                   LayoutTableRow {TR} at (0,2) size 128x49
                     LayoutTableCell {TD} at (2,2) size 124x49 [border: (1px inset #808080)] [r=0 c=0 rs=1 cs=1]
                       LayoutImage {IMG} at (3,3) size 118x25
-                      RenderBR {BR} at (121,28) size 0x0
+                      LayoutBR {BR} at (121,28) size 0x0
                       RenderText {#text} at (24,28) size 6x18
                         text run at (24,28) width 6: "["
                       RenderInline {I} at (0,0) size 66x18