Add Media Router issue-banner.

chrome/browser/resources/media_router/elements/issue_banner/issue_banner.js

+// Copyright 2015 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.
+
+Polymer('issue-banner', {
+  publish: {
+    /**
+     * The issue to show.
+     *
+     * @attribute issue
+     * @type {media_router.Issue}
+     * @default: null
+     */
+    issue: null
+  },
+
+  /**
+   * Fires an issue-action-click event. This is called when an issue action
+   * is clicked.
+   *
+   * @param {!Event} event The event object.
+   * @param {Object} detail The details of the event.
+   * @param {!Element} sender Reference to clicked node.
+   */
+  onClickAction: function(event, detail, sender) {
+    this.fire('issue-action-click', {
+      id: this.issue.id,
+      actionType: parseInt(sender.title),
+      helpURL: this.issue.helpURL
+    });
+  }
+});