Move and rename RenderBR to LayoutBR.

LayoutTests/platform/mac/fast/forms/disabled-select-change-index-expected.txt

Index: LayoutTests/platform/mac/fast/forms/disabled-select-change-index-expected.txt
diff --git a/LayoutTests/platform/mac/fast/forms/disabled-select-change-index-expected.txt b/LayoutTests/platform/mac/fast/forms/disabled-select-change-index-expected.txt
index 208a1c8d01f230d148a309a38e41d78e7ab82d66..d174719c65bc5504eefdde69a184f61e2cbe56a9 100644
--- a/LayoutTests/platform/mac/fast/forms/disabled-select-change-index-expected.txt
+++ b/LayoutTests/platform/mac/fast/forms/disabled-select-change-index-expected.txt
@@ -7,50 +7,50 @@ layer at (0,0) size 800x600
         RenderBlock (anonymous) at (0,0) size 57x18
           RenderText at (8,2) size 26x13
             text run at (8,2) width 26: "PASS"
-      RenderBR {BR} at (57,13) size 0x0
+      LayoutBR {BR} at (57,13) size 0x0
       RenderMenuList {SELECT} at (0,18) size 57x18 [color=#808080] [bgcolor=#F8F8F8]
         RenderBlock (anonymous) at (0,0) size 57x18
           RenderText at (8,2) size 26x13
             text run at (8,2) width 26: "PASS"
-      RenderBR {BR} at (57,31) size 0x0
+      LayoutBR {BR} at (57,31) size 0x0
       RenderMenuList {SELECT} at (0,36) size 57x18 [bgcolor=#F8F8F8]
         RenderBlock (anonymous) at (0,0) size 57x18
           RenderText at (8,2) size 26x13
             text run at (8,2) width 26: "PASS"
-      RenderBR {BR} at (57,49) size 0x0
+      LayoutBR {BR} at (57,49) size 0x0
       RenderMenuList {SELECT} at (0,54) size 57x18 [bgcolor=#F8F8F8]
         RenderBlock (anonymous) at (0,0) size 57x18
           RenderText at (8,2) size 26x13
             text run at (8,2) width 26: "PASS"
-      RenderBR {BR} at (57,67) size 0x0
-      RenderBR {BR} at (42,98) size 1x0
-      RenderBR {BR} at (42,127) size 1x0
-      RenderBR {BR} at (42,156) size 1x0
-      RenderBR {BR} at (42,185) size 1x0
+      LayoutBR {BR} at (57,67) size 0x0
+      LayoutBR {BR} at (42,98) size 1x0
+      LayoutBR {BR} at (42,127) size 1x0
+      LayoutBR {BR} at (42,156) size 1x0
+      LayoutBR {BR} at (42,185) size 1x0
       RenderText {#text} at (0,188) size 497x18
         text run at (0,188) width 497: "PASS: sel1 correctly set to selectedIndex 1 by sel1.options[1].selected = true."
-      RenderBR {BR} at (496,202) size 1x0
+      LayoutBR {BR} at (496,202) size 1x0
       RenderText {#text} at (0,206) size 447x18
         text run at (0,206) width 447: "PASS: sel2 correctly set to selectedIndex 1 by sel2.selectedIndex = 1."
-      RenderBR {BR} at (446,220) size 1x0
+      LayoutBR {BR} at (446,220) size 1x0
       RenderText {#text} at (0,224) size 497x18
         text run at (0,224) width 497: "PASS: sel3 correctly set to selectedIndex 1 by sel3.options[1].selected = true."
-      RenderBR {BR} at (496,238) size 1x0
+      LayoutBR {BR} at (496,238) size 1x0
       RenderText {#text} at (0,242) size 447x18
         text run at (0,242) width 447: "PASS: sel4 correctly set to selectedIndex 1 by sel4.selectedIndex = 1."
-      RenderBR {BR} at (446,256) size 1x0
+      LayoutBR {BR} at (446,256) size 1x0
       RenderText {#text} at (0,260) size 497x18
         text run at (0,260) width 497: "PASS: sel5 correctly set to selectedIndex 1 by sel5.options[1].selected = true."
-      RenderBR {BR} at (496,274) size 1x0
+      LayoutBR {BR} at (496,274) size 1x0
       RenderText {#text} at (0,278) size 447x18
         text run at (0,278) width 447: "PASS: sel6 correctly set to selectedIndex 1 by sel6.selectedIndex = 1."
-      RenderBR {BR} at (446,292) size 1x0
+      LayoutBR {BR} at (446,292) size 1x0
       RenderText {#text} at (0,296) size 497x18
         text run at (0,296) width 497: "PASS: sel7 correctly set to selectedIndex 1 by sel7.options[1].selected = true."
-      RenderBR {BR} at (496,310) size 1x0
+      LayoutBR {BR} at (496,310) size 1x0
       RenderText {#text} at (0,314) size 447x18
         text run at (0,314) width 447: "PASS: sel8 correctly set to selectedIndex 1 by sel8.selectedIndex = 1."
-      RenderBR {BR} at (446,328) size 1x0
+      LayoutBR {BR} at (446,328) size 1x0
 layer at (8,80) size 43x30 clip at (9,81) size 30x28
   RenderListBox {SELECT} at (0,71.63) size 42.53x30.38 [color=#7F7F7F] [bgcolor=#FFFFFF] [border: (1px solid #999999)]
     RenderBlock {OPTION} at (1,1) size 29.53x14.19