Remove the "horizontal-bt" value from -webkit-writing-mode

third_party/WebKit/LayoutTests/css3/flexbox/flex-flow-margins.html

Index: third_party/WebKit/LayoutTests/css3/flexbox/flex-flow-margins.html
diff --git a/third_party/WebKit/LayoutTests/css3/flexbox/flex-flow-margins.html b/third_party/WebKit/LayoutTests/css3/flexbox/flex-flow-margins.html
index 9ecadd86e33813443a7e38085470818f027c0596..e9a9f9b48e3c93b9626cbaf7e8fc0ae0e37e8d2c 100644
--- a/third_party/WebKit/LayoutTests/css3/flexbox/flex-flow-margins.html
+++ b/third_party/WebKit/LayoutTests/css3/flexbox/flex-flow-margins.html
@@ -25,9 +25,6 @@
 .horizontal-tb {
     -webkit-writing-mode: horizontal-tb;
 }
-.horizontal-bt {
-    -webkit-writing-mode: horizontal-bt;
-}
 .vertical-rl {
     -webkit-writing-mode: vertical-rl;
 }
@@ -106,20 +103,6 @@ var physicalExpectations = {
             row: [90, 20, 48, 23]
         }
     },
-    'horizontal-bt': {
-        rtl: {
-            container: physicalContainerSize,
-            flexbox: physicalFlexBoxPosition,
-            column: [20, 70, 118, 23],
-            row: [90, 20, 48, 73]
-        },
-        ltr : {
-            container: physicalContainerSize,
-            flexbox: physicalFlexBoxPosition,
-            column: [20, 70, 48, 23],
-            row: [90, 20, 48, 73]
-        }
-    },
     'vertical-lr': {
         rtl: {
             container: physicalContainerSize,
@@ -165,20 +148,6 @@ var logicalExpectations = {
             row: [90, 20, 48, 23]
         }
     },
-    'horizontal-bt': {
-        rtl: {
-            container: [160, 140],
-            flexbox: [20, 30],
-            column: [20, 70, 92, 47],
-            row: [90, 20, 22, 97]
-        },
-        ltr : {
-            container: [160, 140],
-            flexbox: [40, 30],
-            column: [20, 70, 48, 47],
-            row: [90, 20, 48, 97]
-        }
-    },
     'vertical-lr': {
         rtl: {
             container: [140, 160],
@@ -209,7 +178,7 @@ var logicalExpectations = {
     }
 }
 
-var writingModes = ['horizontal-tb', 'horizontal-bt', 'vertical-lr', 'vertical-rl'];
+var writingModes = ['horizontal-tb', 'vertical-lr', 'vertical-rl'];
 var flexFlows = ['row', 'column', 'row-reverse', 'row-reverse'];
 var directions = ['rtl', 'ltr'];
 var marginTypes = ['physical', 'logical'];