Move and rename RenderBR to LayoutBR.

LayoutTests/platform/mac/fast/forms/input-appearance-height-expected.txt

 layer at (0,0) size 800x600
   RenderView at (0,0) size 800x600
 layer at (0,0) size 800x600
   RenderBlock {HTML} at (0,0) size 800x600
     RenderBody {BODY} at (8,8) size 784x576
       RenderBlock (anonymous) at (0,0) size 784x18
         RenderText {#text} at (0,0) size 781x18
           text run at (0,0) width 781: "This tests the height attribute of form elements. The only element that should honour this value is the Image type of input."
       RenderBlock {FORM} at (0,18) size 784x229
         RenderText {#text} at (0,0) size 37x18
           text run at (0,0) width 37: "input "
         LayoutTextControl {INPUT} at (36.89,0) size 123x19 [bgcolor=#FFFFFF] [border: (2px inset #EEEEEE)]
         RenderText {#text} at (159,0) size 5x18
           text run at (159,0) width 5: " "
-        RenderBR {BR} at (163,14) size 1x0
+        LayoutBR {BR} at (163,14) size 1x0
         RenderText {#text} at (0,19) size 28x18
           text run at (0,19) width 28: "text "
         LayoutTextControl {INPUT} at (27.98,19) size 123x19 [bgcolor=#FFFFFF] [border: (2px inset #EEEEEE)]
         RenderText {#text} at (150,19) size 5x18
           text run at (150,19) width 5: " "
-        RenderBR {BR} at (154,33) size 1x0
+        LayoutBR {BR} at (154,33) size 1x0
         RenderText {#text} at (0,38) size 66x18
           text run at (0,38) width 66: "checkbox "
         RenderBlock {INPUT} at (68.20,42) size 12x12
         RenderText {#text} at (83,38) size 5x18
           text run at (83,38) width 5: " "
-        RenderBR {BR} at (87,52) size 1x0
+        LayoutBR {BR} at (87,52) size 1x0
         RenderText {#text} at (0,57) size 26x18
           text run at (0,57) width 26: "file "
         RenderFileUploadControl {INPUT} at (25.31,58) size 237x18 "No file chosen"
           RenderButton {INPUT} at (0,0) size 77.56x18 [bgcolor=#C0C0C0]
             RenderBlock (anonymous) at (8,2) size 61.56x13
               RenderText {#text} at (0,0) size 62x13
                 text run at (0,0) width 62: "Choose File"
         RenderText {#text} at (262,57) size 5x18
           text run at (262,57) width 5: " "
-        RenderBR {BR} at (266,71) size 1x0
+        LayoutBR {BR} at (266,71) size 1x0
         RenderText {#text} at (0,76) size 44x18
           text run at (0,76) width 44: "image "
         LayoutImage {INPUT} at (43.09,89) size 10x1
         RenderText {#text} at (53,76) size 5x18
           text run at (53,76) width 5: " "
-        RenderBR {BR} at (57,90) size 1x0
+        LayoutBR {BR} at (57,90) size 1x0
         RenderText {#text} at (0,94) size 37x18
           text run at (0,94) width 37: "radio "
         RenderBlock {INPUT} at (39.78,97) size 12x13
         RenderText {#text} at (54,94) size 5x18
           text run at (54,94) width 5: " "
-        RenderBR {BR} at (58,108) size 1x0
+        LayoutBR {BR} at (58,108) size 1x0
         RenderText {#text} at (0,116) size 40x18
           text run at (0,116) width 40: "range "
         LayoutSlider {INPUT} at (41.53,115) size 129x15 [color=#909090] [bgcolor=#FFFFFF]
           RenderFlexibleBox {DIV} at (0,0) size 129x15
             RenderBlock {DIV} at (0,0) size 129x15
               RenderBlock {DIV} at (57,0) size 15x15
         RenderText {#text} at (172,116) size 5x18
           text run at (172,116) width 5: " "
-        RenderBR {BR} at (176,130) size 1x0
+        LayoutBR {BR} at (176,130) size 1x0
         RenderText {#text} at (0,134) size 35x18
           text run at (0,134) width 35: "reset "
         RenderButton {INPUT} at (34.20,135) size 44.94x18 [bgcolor=#C0C0C0]
           RenderBlock (anonymous) at (8,2) size 28.94x13
             RenderText {#text} at (0,0) size 29x13
               text run at (0,0) width 29: "Reset"
         RenderText {#text} at (79,134) size 5x18
           text run at (79,134) width 5: " "
-        RenderBR {BR} at (83,148) size 1x0
+        LayoutBR {BR} at (83,148) size 1x0
         RenderText {#text} at (0,153) size 48x18
           text run at (0,153) width 48: "submit "
         RenderButton {INPUT} at (47.56,154) size 53.25x18 [bgcolor=#C0C0C0]
           RenderBlock (anonymous) at (8,2) size 37.25x13
             RenderText {#text} at (0,0) size 38x13
               text run at (0,0) width 38: "Submit"
         RenderText {#text} at (100,153) size 5x18
           text run at (100,153) width 5: " "
-        RenderBR {BR} at (104,167) size 1x0
+        LayoutBR {BR} at (104,167) size 1x0
         RenderText {#text} at (0,172) size 51x18
           text run at (0,172) width 51: "isindex "
         LayoutTextControl {INPUT} at (50.22,172) size 123x19 [bgcolor=#FFFFFF] [border: (2px inset #EEEEEE)]
         RenderText {#text} at (173,172) size 5x18
           text run at (173,172) width 5: " "
-        RenderBR {BR} at (177,186) size 1x0
+        LayoutBR {BR} at (177,186) size 1x0
         RenderText {#text} at (0,191) size 65x18
           text run at (0,191) width 65: "password "
         LayoutTextControl {INPUT} at (64.44,191) size 123x19 [bgcolor=#FFFFFF] [border: (2px inset #EEEEEE)]
         RenderText {#text} at (187,191) size 5x18
           text run at (187,191) width 5: " "
-        RenderBR {BR} at (191,205) size 1x0
+        LayoutBR {BR} at (191,205) size 1x0
         RenderText {#text} at (0,210) size 45x18
           text run at (0,210) width 45: "search "
         LayoutTextControl {INPUT} at (44.86,210) size 125x19 [bgcolor=#FFFFFF] [border: (2px inset #EEEEEE)]
           RenderFlexibleBox {DIV} at (4,3) size 117x13
             RenderBlock {DIV} at (0,6.50) size 5x0
             RenderBlock {DIV} at (5,0) size 100x13
         RenderText {#text} at (0,0) size 0x0
 layer at (48,29) size 117x13
   RenderBlock {DIV} at (3,3) size 117x13
 layer at (39,48) size 117x13
   RenderBlock {DIV} at (3,3) size 117x13
 layer at (61,201) size 117x13
   RenderBlock {DIV} at (3,3) size 117x13
 layer at (75,220) size 117x13
   RenderBlock {DIV} at (3,3) size 117x13
 layer at (62,239) size 100x13
   RenderBlock {DIV} at (0,0) size 100x13
 layer at (163,240) size 11x11 transparent
   RenderBlock {DIV} at (106,1) size 11x11