Move and rename RenderBR to LayoutBR.

LayoutTests/platform/mac/fast/forms/select-baseline-expected.txt

Index: LayoutTests/platform/mac/fast/forms/select-baseline-expected.txt
diff --git a/LayoutTests/platform/mac/fast/forms/select-baseline-expected.txt b/LayoutTests/platform/mac/fast/forms/select-baseline-expected.txt
index 8f27f2cc595d35dd3c2055811fbf6e42b9281f72..485874ff94d46ea40810e6cfdc47a54ac6f7c44b 100644
--- a/LayoutTests/platform/mac/fast/forms/select-baseline-expected.txt
+++ b/LayoutTests/platform/mac/fast/forms/select-baseline-expected.txt
@@ -5,10 +5,10 @@ layer at (0,0) size 800x600
     RenderBody {BODY} at (8,8) size 784x584
       RenderText {#text} at (0,0) size 474x18
         text run at (0,0) width 474: "This tests that empty select controls and buttons have the correct baseline."
-      RenderBR {BR} at (473,14) size 1x0
+      LayoutBR {BR} at (473,14) size 1x0
       RenderMenuList {SELECT} at (0,20) size 36x18 [bgcolor=#F8F8F8]
         RenderBlock (anonymous) at (0,0) size 36x18
-          RenderBR at (8,2) size 0x13 [bgcolor=#F8F8F8]
+          LayoutBR at (8,2) size 0x13 [bgcolor=#F8F8F8]
       RenderText {#text} at (36,19) size 31x18
         text run at (36,19) width 31: " test "
       RenderMenuList {SELECT} at (66.22,20) size 51x18 [bgcolor=#F8F8F8]
@@ -19,7 +19,7 @@ layer at (0,0) size 800x600
         text run at (117,19) width 5: " "
       RenderMenuList {SELECT} at (121.22,20) size 36x18 [color=#00008B] [bgcolor=#ADD8E6] [border: (1px solid #A6A6A6)]
         RenderBlock (anonymous) at (1,1) size 34x16
-          RenderBR at (8,1) size 0x13 [bgcolor=#ADD8E6]
+          LayoutBR at (8,1) size 0x13 [bgcolor=#ADD8E6]
       RenderText {#text} at (157,19) size 31x18
         text run at (157,19) width 31: " test "
       RenderMenuList {SELECT} at (187.44,20) size 51x18 [color=#00008B] [bgcolor=#ADD8E6] [border: (1px solid #A6A6A6)]