Add test that would fail with the "last style" behavior in master

test/unit/styling-scoped.html

@@ -691,6 +691,30 @@
     </script>
   </dom-module>
 
+  <dom-module id="x-interleaved-styles">
+    <template>
+      <style include="x-nested-style"></style>
+      <style>
+        :host {
+          padding-top: 5px;
+        }
+      </style>
+      <style>
+        :host {
+          color: blue;
+        }
+      </style>
+    </template>
+    <script>
+      addEventListener('WebComponentsReady', () => {
+        class XInterleaved extends Polymer.Element {
+          static get is() {return 'x-interleaved-styles';}
+        }
+        customElements.define(XInterleaved.is, XInterleaved);
+      });
+    </script>
+  </dom-module>
+
 <script>
 (function() {
   function assertComputed(element, value, property, pseudo) {
@@ -955,6 +979,12 @@
       assertComputed(e, '10px', 'padding-top');
     });
 
+    test('interleaved styles and styles with includes work as expected', function() {
+      var e = document.createElement('x-interleaved-styles');
+      document.body.appendChild(e);
+      assertComputed(e, '5px', 'padding-top');
+    });
+
   });
 
   if (window.ShadyDOM) {