Use webkit-margin-end for details element to get same margin for both ltr and rtl

RenderDetailMarker needs both left and right margin to get rendered with same margin. Updated with webkit-margin-end to get the same margin result for both ltr and rtl

R=eseidel, leviw, tkent
BUG=335075
TEST=Existing details-writing-mode covers test for showing text in RTL box, with the patch rtl box now shows margin which is currently missing.

Review URL: https://codereview.chromium.org/306923003

git-svn-id: svn://svn.chromium.org/blink/trunk@176016 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/TestExpectations

@@ -61,6 +61,9 @@ crbug.com/245611 [ Linux ] fast/hidpi/video-controls-in-hidpi.html [ ImageOnlyFa
 
 crbug.com/304953 fast/css/font-face-download-error.html [ Pass Timeout ]
 
+crbug.com/335075 fast/html/details-writing-mode.html [ NeedsRebaseline ]
+crbug.com/335075 fast/html/details-marker-style.html [ NeedsRebaseline ]
+
 # This batch were marked as NeedsRebaseline for crbug.com/133097 but are flaky:
 crbug.com/310679 [ Mac ] compositing/fixed-body-background-positioned.html [ Failure Pass ]
 crbug.com/310679 [ Mac ] compositing/rubberbanding/transform-overhang-e.html [ ImageOnlyFailure Pass ]

third_party/WebKit/Source/core/css/html.css

@@ -1128,7 +1128,7 @@ summary::-webkit-details-marker {
     display: inline-block;
     width: 0.66em;
     height: 0.66em;
-    margin-right: 0.4em;
+    -webkit-margin-end: 0.4em;
 }
 
 template {