Upgrade to 1.0 and switch clients to dom-repeat where needed.

third_party/polymer/v0_8/components/iron-overlay-behavior/iron-overlay-backdrop.html

+<!--
+@license
+Copyright (c) 2015 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+
+<link rel="import" href="../polymer/polymer.html">
+<link rel="import" href="iron-overlay-manager.html">
+
+<!--
+`iron-overlay-backdrop` is a backdrop used by `Polymer.IronOverlayBehavior`. It should be a
+singleton.
+
+### Styling
+
+The following custom properties and mixins are available for styling.
+
+Custom property | Description | Default
+-------------------------------------------|------------------------|---------
+`--iron-overlay-backdrop-background-color` | Backdrop background color                                     | #000
+`--iron-overlay-backdrop-opacity`          | Backdrop opacity                                              | 0.6
+`--iron-overlay-backdrop`                  | Mixin applied to `iron-overlay-backdrop`.                      | {}
+`--iron-overlay-backdrop-opened`           | Mixin applied to `iron-overlay-backdrop` when it is displayed | {}
+-->
+
+<dom-module id="iron-overlay-backdrop">
+
+  <style>
+
+    :host {
+      position: fixed;
+      top: 0;
+      left: 0;
+      width: 100vw;
+      height: 100vh;
+      background-color: var(--iron-overlay-backdrop-background-color, #000);
+      opacity: 0;
+      transition: opacity 0.2s;
+
+      @apply(--iron-overlay-backdrop);
+    }
+
+    :host([opened]) {
+      opacity: var(--iron-overlay-backdrop-opacity, 0.6);
+
+      @apply(--iron-overlay-backdrop-opened);
+    }
+
+  </style>
+
+  <template>
+    <content></content>
+  </template>
+
+</dom-module>
+
+<script>
+
+(function() {
+
+  Polymer({
+
+    is: 'iron-overlay-backdrop',
+
+    properties: {
+
+      /**
+       * Returns true if the backdrop is opened.
+       */
+      opened: {
+        readOnly: true,
+        reflectToAttribute: true,
+        type: Boolean,
+        value: false
+      },
+
+      _manager: {
+        type: Object,
+        value: Polymer.IronOverlayManager
+      }
+
+    },
+
+    /**
+     * Appends the backdrop to document body and sets its `z-index` to be below the latest overlay.
+     */
+    prepare: function() {
+      if (!this.parentNode) {
+        Polymer.dom(document.body).appendChild(this);
+        this.style.zIndex = this._manager.currentOverlayZ() - 1;
+      }
+    },
+
+    /**
+     * Shows the backdrop if needed.
+     */
+    open: function() {
+      // only need to make the backdrop visible if this is called by the first overlay with a backdrop
+      if (this._manager.getBackdrops().length < 2) {
+        this._setOpened(true);
+      }
+    },
+
+    /**
+     * Hides the backdrop if needed.
+     */
+    close: function() {
+      // only need to make the backdrop invisible if this is called by the last overlay with a backdrop
+      if (this._manager.getBackdrops().length < 2) {
+        this._setOpened(false);
+      }
+    },
+
+    /**
+     * Removes the backdrop from document body if needed.
+     */
+    complete: function() {
+      // only remove the backdrop if there are no more overlays with backdrops
+      if (this._manager.getBackdrops().length === 0 && this.parentNode) {
+        Polymer.dom(this.parentNode).removeChild(this);
+      }
+    }
+
+  });
+
+})();
+
+</script>