Set article spacing in dp, not px.

chrome/android/java/res/drawable/snippet_separator.xml

Index: chrome/android/java/res/drawable/snippet_separator.xml
diff --git a/chrome/android/java/res/drawable-sw600dp/bg_white_dialog.xml b/chrome/android/java/res/drawable/snippet_separator.xml
similarity index 57%
copy from chrome/android/java/res/drawable-sw600dp/bg_white_dialog.xml
copy to chrome/android/java/res/drawable/snippet_separator.xml
index f384c955175b09899d1807ea2310eb96d72d59f0..877135837cc2137f3509fb55bb4088eeec8d1b6f 100644
--- a/chrome/android/java/res/drawable-sw600dp/bg_white_dialog.xml
+++ b/chrome/android/java/res/drawable/snippet_separator.xml
@@ -1,12 +1,12 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!-- Copyright 2015 The Chromium Authors. All rights reserved.
+<!-- Copyright 2016 The Chromium Authors. All rights reserved.
      Use of this source code is governed by a BSD-style license that can be
      found in the LICENSE file. -->
 
 <shape xmlns:android="http://schemas.android.com/apk/res/android"
     android:shape="rectangle">
-    <corners
-        android:radius="2dp" />
     <solid
-        android:color="@android:color/white" />
+        android:color="@color/snippets_separator" />
+    <size
+        android:height="@dimen/snippets_vertical_spacing" />
 </shape>