Fix selection handles in vertical writing modes.

third_party/WebKit/Source/web/tests/data/composited_selection_bounds_vertical.html

Index: third_party/WebKit/Source/web/tests/data/composited_selection_bounds_vertical.html
diff --git a/third_party/WebKit/Source/web/tests/data/composited_selection_bounds_basic.html b/third_party/WebKit/Source/web/tests/data/composited_selection_bounds_vertical.html
similarity index 75%
copy from third_party/WebKit/Source/web/tests/data/composited_selection_bounds_basic.html
copy to third_party/WebKit/Source/web/tests/data/composited_selection_bounds_vertical.html
index 962418581e36ae592045e802c0453b07ec632c27..3ddfb245d34fe7f40522d4fb7f847cf7a809523e 100644
--- a/third_party/WebKit/Source/web/tests/data/composited_selection_bounds_basic.html
+++ b/third_party/WebKit/Source/web/tests/data/composited_selection_bounds_vertical.html
@@ -6,6 +6,9 @@
     * {
         font-family: ahem;
     }
+    body {
+      -webkit-writing-mode: vertical-rl;

[kojii, 2015/12/16 17:30:58]

Can you also add a test for |vertical-lr|?

[aelias_OOO_until_Jul13, 2016/01/08 02:24:12]

Done.

+    }
 </style>
 <span id="text">
     The quick brown fox jumped over the lazy dog.
@@ -17,6 +20,6 @@
     range.setEnd(textNode, 25);
     document.getSelection().addRange(range);
 
-    window.expectedResult = [document, 68, 8, 68, 20, document, 248, 8, 248, 20];
+    window.expectedResult = [document, 620, 68, 632, 68, document, 632, 248, 620, 248];
 </script>