Move and rename RenderBR to LayoutBR.

LayoutTests/platform/linux/fast/css/text-rendering-expected.txt

Index: LayoutTests/platform/linux/fast/css/text-rendering-expected.txt
diff --git a/LayoutTests/platform/linux/fast/css/text-rendering-expected.txt b/LayoutTests/platform/linux/fast/css/text-rendering-expected.txt
index 9e2e2be1d434879c71d670289e9d7b70f05ffb09..fe90439101d3192fb916657d91ac98f4841d80c7 100644
--- a/LayoutTests/platform/linux/fast/css/text-rendering-expected.txt
+++ b/LayoutTests/platform/linux/fast/css/text-rendering-expected.txt
@@ -9,25 +9,25 @@ layer at (0,0) size 800x600
           text run at (0,72) width 227: "ligatures)"
       RenderText {#text} at (227,111) size 4x19
         text run at (227,111) width 4: " "
-      RenderBR {BR} at (231,126) size 0x0
+      LayoutBR {BR} at (231,126) size 0x0
       RenderInline {SPAN} at (0,0) size 670x139
         RenderText {#text} at (0,143) size 670x139
           text run at (0,143) width 670: "fin LYAWA (No kerning or"
           text run at (0,214) width 227: "ligatures)"
       RenderText {#text} at (227,253) size 4x19
         text run at (227,253) width 4: " "
-      RenderBR {BR} at (231,268) size 0x0
+      LayoutBR {BR} at (231,268) size 0x0
       RenderInline {SPAN} at (0,0) size 604x139
         RenderText {#text} at (0,285) size 604x139
           text run at (0,285) width 604: "fin LYAWA (Kerning and"
           text run at (0,356) width 227: "ligatures)"
       RenderText {#text} at (227,395) size 4x19
         text run at (227,395) width 4: " "
-      RenderBR {BR} at (231,410) size 0x0
+      LayoutBR {BR} at (231,410) size 0x0
       RenderInline {SPAN} at (0,0) size 604x139
         RenderText {#text} at (0,427) size 604x139
           text run at (0,427) width 604: "fin LYAWA (Kerning and"
           text run at (0,498) width 227: "ligatures)"
       RenderText {#text} at (227,537) size 4x19
         text run at (227,537) width 4: " "
-      RenderBR {BR} at (231,552) size 0x0
+      LayoutBR {BR} at (231,552) size 0x0