Move and rename RenderBR to LayoutBR.

LayoutTests/platform/mac/editing/input/emacs-ctrl-o-expected.txt

Index: LayoutTests/platform/mac/editing/input/emacs-ctrl-o-expected.txt
diff --git a/LayoutTests/platform/mac/editing/input/emacs-ctrl-o-expected.txt b/LayoutTests/platform/mac/editing/input/emacs-ctrl-o-expected.txt
index 823387fd6fafc41be137b50bec6c262860f5e628..a8aa2e63d9edfa53e2f93e99dad18a88d4c90dce 100644
--- a/LayoutTests/platform/mac/editing/input/emacs-ctrl-o-expected.txt
+++ b/LayoutTests/platform/mac/editing/input/emacs-ctrl-o-expected.txt
@@ -11,16 +11,16 @@ layer at (0,0) size 800x600
         RenderBlock {DIV} at (0,0) size 784x56
           RenderText {#text} at (0,0) size 62x28
             text run at (0,0) width 62: "Tests:"
-          RenderBR {BR} at (61,22) size 1x0
+          LayoutBR {BR} at (61,22) size 1x0
           RenderText {#text} at (0,28) size 253x28
             text run at (0,28) width 253: "Key binding for control-O"
         RenderBlock {DIV} at (0,72) size 784x84
           RenderText {#text} at (0,0) size 177x28
             text run at (0,0) width 177: "Expected results:"
-          RenderBR {BR} at (176,22) size 1x0
+          LayoutBR {BR} at (176,22) size 1x0
           RenderText {#text} at (0,28) size 89x28
             text run at (0,28) width 89: "one five |"
-          RenderBR {BR} at (88,50) size 1x0
+          LayoutBR {BR} at (88,50) size 1x0
           RenderText {#text} at (0,56) size 136x28
             text run at (0,56) width 136: "two three four"
       RenderBlock {DIV} at (0,180) size 784x28