Move and rename RenderBR to LayoutBR.

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

Index: LayoutTests/platform/mac/fast/borders/border-antialiasing-expected.txt
diff --git a/LayoutTests/platform/mac/fast/borders/border-antialiasing-expected.txt b/LayoutTests/platform/mac/fast/borders/border-antialiasing-expected.txt
index 79ed08a5517d9cfc3e9efd10efe1494cd0c50a24..870e1d8435536d556cd47ffeed4710221a2bda19 100644
--- a/LayoutTests/platform/mac/fast/borders/border-antialiasing-expected.txt
+++ b/LayoutTests/platform/mac/fast/borders/border-antialiasing-expected.txt
@@ -101,7 +101,7 @@ layer at (18,20) size 764x431
       RenderInline {SPAN} at (0,0) size 80x40
         RenderText {#text} at (6,0) size 74x18
           text run at (6,0) width 74: "I am a span"
-        RenderBR {BR} at (79,0) size 1x18
+        LayoutBR {BR} at (79,0) size 1x18
         RenderText {#text} at (0,18) size 29x18
           text run at (0,18) width 29: "I am"
       RenderText {#text} at (34,18) size 5x18
@@ -109,7 +109,7 @@ layer at (18,20) size 764x431
       RenderInline {SPAN} at (0,0) size 76x40
         RenderText {#text} at (44,18) size 30x18
           text run at (44,18) width 30: "I am"
-        RenderBR {BR} at (73,18) size 1x18
+        LayoutBR {BR} at (73,18) size 1x18
         RenderText {#text} at (0,36) size 74x18
           text run at (0,36) width 74: "a span I am"
       RenderText {#text} at (79,36) size 5x18
@@ -117,7 +117,7 @@ layer at (18,20) size 764x431
       RenderInline {SPAN} at (0,0) size 163x40
         RenderText {#text} at (89,36) size 74x18
           text run at (89,36) width 74: "I am a span"
-        RenderBR {BR} at (162,36) size 1x18
+        LayoutBR {BR} at (162,36) size 1x18
         RenderText {#text} at (0,54) size 29x18
           text run at (0,54) width 29: "I am"
       RenderText {#text} at (34,54) size 5x18
@@ -125,7 +125,7 @@ layer at (18,20) size 764x431
       RenderInline {SPAN} at (0,0) size 76x40
         RenderText {#text} at (44,54) size 30x18
           text run at (44,54) width 30: "I am"
-        RenderBR {BR} at (73,54) size 1x18
+        LayoutBR {BR} at (73,54) size 1x18
         RenderText {#text} at (0,72) size 74x18
           text run at (0,72) width 74: "a span I am"
       RenderText {#text} at (79,72) size 5x18
@@ -133,7 +133,7 @@ layer at (18,20) size 764x431
       RenderInline {SPAN} at (0,0) size 163x40
         RenderText {#text} at (89,72) size 74x18
           text run at (89,72) width 74: "I am a span"
-        RenderBR {BR} at (162,72) size 1x18
+        LayoutBR {BR} at (162,72) size 1x18
         RenderText {#text} at (0,90) size 29x18
           text run at (0,90) width 29: "I am"
       RenderText {#text} at (34,90) size 5x18
@@ -141,7 +141,7 @@ layer at (18,20) size 764x431
       RenderInline {SPAN} at (0,0) size 76x40
         RenderText {#text} at (44,90) size 30x18
           text run at (44,90) width 30: "I am"
-        RenderBR {BR} at (73,90) size 1x18
+        LayoutBR {BR} at (73,90) size 1x18
         RenderText {#text} at (0,108) size 74x18
           text run at (0,108) width 74: "a span I am"
       RenderText {#text} at (79,108) size 5x18
@@ -149,7 +149,7 @@ layer at (18,20) size 764x431
       RenderInline {SPAN} at (0,0) size 163x40
         RenderText {#text} at (89,108) size 74x18
           text run at (89,108) width 74: "I am a span"
-        RenderBR {BR} at (162,108) size 1x18
+        LayoutBR {BR} at (162,108) size 1x18
         RenderText {#text} at (0,126) size 29x18
           text run at (0,126) width 29: "I am"
       RenderText {#text} at (34,126) size 5x18
@@ -157,7 +157,7 @@ layer at (18,20) size 764x431
       RenderInline {SPAN} at (0,0) size 76x40
         RenderText {#text} at (44,126) size 30x18
           text run at (44,126) width 30: "I am"
-        RenderBR {BR} at (73,126) size 1x18
+        LayoutBR {BR} at (73,126) size 1x18
         RenderText {#text} at (0,144) size 74x18
           text run at (0,144) width 74: "a span I am"
       RenderText {#text} at (0,0) size 0x0