Move and rename RenderBR to LayoutBR.

LayoutTests/platform/linux/fast/borders/border-antialiasing-expected.txt

Index: LayoutTests/platform/linux/fast/borders/border-antialiasing-expected.txt
diff --git a/LayoutTests/platform/linux/fast/borders/border-antialiasing-expected.txt b/LayoutTests/platform/linux/fast/borders/border-antialiasing-expected.txt
index d83dd6ca4b227d3064558215745fc39b3407eea7..9b9f12d9ccac137d643980b3567698f7cd1ea972 100644
--- a/LayoutTests/platform/linux/fast/borders/border-antialiasing-expected.txt
+++ b/LayoutTests/platform/linux/fast/borders/border-antialiasing-expected.txt
@@ -101,7 +101,7 @@ layer at (18,20) size 764x449
       RenderInline {SPAN} at (0,0) size 76x43
         RenderText {#text} at (6,0) size 70x19
           text run at (6,0) width 70: "I am a span"
-        RenderBR {BR} at (76,0) size 0x19
+        LayoutBR {BR} at (76,0) size 0x19
         RenderText {#text} at (0,20) size 27x19
           text run at (0,20) width 27: "I am"
       RenderText {#text} at (33,20) size 4x19
@@ -109,7 +109,7 @@ layer at (18,20) size 764x449
       RenderInline {SPAN} at (0,0) size 72x43
         RenderText {#text} at (43,20) size 27x19
           text run at (43,20) width 27: "I am"
-        RenderBR {BR} at (70,20) size 0x19
+        LayoutBR {BR} at (70,20) size 0x19
         RenderText {#text} at (0,40) size 70x19
           text run at (0,40) width 70: "a span I am"
       RenderText {#text} at (76,40) size 4x19
@@ -117,7 +117,7 @@ layer at (18,20) size 764x449
       RenderInline {SPAN} at (0,0) size 156x43
         RenderText {#text} at (86,40) size 70x19
           text run at (86,40) width 70: "I am a span"
-        RenderBR {BR} at (156,40) size 0x19
+        LayoutBR {BR} at (156,40) size 0x19
         RenderText {#text} at (0,60) size 27x19
           text run at (0,60) width 27: "I am"
       RenderText {#text} at (33,60) size 4x19
@@ -125,7 +125,7 @@ layer at (18,20) size 764x449
       RenderInline {SPAN} at (0,0) size 72x43
         RenderText {#text} at (43,60) size 27x19
           text run at (43,60) width 27: "I am"
-        RenderBR {BR} at (70,60) size 0x19
+        LayoutBR {BR} at (70,60) size 0x19
         RenderText {#text} at (0,80) size 70x19
           text run at (0,80) width 70: "a span I am"
       RenderText {#text} at (76,80) size 4x19
@@ -133,7 +133,7 @@ layer at (18,20) size 764x449
       RenderInline {SPAN} at (0,0) size 156x43
         RenderText {#text} at (86,80) size 70x19
           text run at (86,80) width 70: "I am a span"
-        RenderBR {BR} at (156,80) size 0x19
+        LayoutBR {BR} at (156,80) size 0x19
         RenderText {#text} at (0,100) size 27x19
           text run at (0,100) width 27: "I am"
       RenderText {#text} at (33,100) size 4x19
@@ -141,7 +141,7 @@ layer at (18,20) size 764x449
       RenderInline {SPAN} at (0,0) size 72x43
         RenderText {#text} at (43,100) size 27x19
           text run at (43,100) width 27: "I am"
-        RenderBR {BR} at (70,100) size 0x19
+        LayoutBR {BR} at (70,100) size 0x19
         RenderText {#text} at (0,120) size 70x19
           text run at (0,120) width 70: "a span I am"
       RenderText {#text} at (76,120) size 4x19
@@ -149,7 +149,7 @@ layer at (18,20) size 764x449
       RenderInline {SPAN} at (0,0) size 156x43
         RenderText {#text} at (86,120) size 70x19
           text run at (86,120) width 70: "I am a span"
-        RenderBR {BR} at (156,120) size 0x19
+        LayoutBR {BR} at (156,120) size 0x19
         RenderText {#text} at (0,140) size 27x19
           text run at (0,140) width 27: "I am"
       RenderText {#text} at (33,140) size 4x19
@@ -157,7 +157,7 @@ layer at (18,20) size 764x449
       RenderInline {SPAN} at (0,0) size 72x43
         RenderText {#text} at (43,140) size 27x19
           text run at (43,140) width 27: "I am"
-        RenderBR {BR} at (70,140) size 0x19
+        LayoutBR {BR} at (70,140) size 0x19
         RenderText {#text} at (0,160) size 70x19
           text run at (0,160) width 70: "a span I am"
       RenderText {#text} at (0,0) size 0x0