Move and rename RenderBR to LayoutBR.

LayoutTests/editing/pasteboard/emacs-ctrl-k-y-001-expected.txt

Index: LayoutTests/editing/pasteboard/emacs-ctrl-k-y-001-expected.txt
diff --git a/LayoutTests/editing/pasteboard/emacs-ctrl-k-y-001-expected.txt b/LayoutTests/editing/pasteboard/emacs-ctrl-k-y-001-expected.txt
index 84b2b6d1087eba886196d1ec1bd42d98234d5754..5256683a44b0c930a312e47bc57c917560b84f81 100644
--- a/LayoutTests/editing/pasteboard/emacs-ctrl-k-y-001-expected.txt
+++ b/LayoutTests/editing/pasteboard/emacs-ctrl-k-y-001-expected.txt
@@ -32,14 +32,14 @@ layer at (0,0) size 800x600
         RenderBlock {DIV} at (14,14) size 756x56
           RenderText {#text} at (0,0) size 67x28
             text run at (0,0) width 67: "Tests: "
-          RenderBR {BR} at (0,0) size 0x0
+          LayoutBR {BR} at (0,0) size 0x0
           RenderText {#text} at (0,28) size 348x28
             text run at (0,28) width 348: "Multiple ctrl-k presses then a ctrl-y."
         RenderBlock {DIV} at (14,86) size 756x112
           RenderBlock (anonymous) at (0,0) size 756x28
             RenderText {#text} at (0,0) size 189x28
               text run at (0,0) width 189: "Expected Results: "
-            RenderBR {BR} at (189,22) size 0x0
+            LayoutBR {BR} at (189,22) size 0x0
           RenderBlock {DIV} at (0,28) size 756x84
             RenderBlock (anonymous) at (0,0) size 756x28
               RenderText {#text} at (0,0) size 132x28