Roll Polymer from 1.5.0 -> 1.6.0 to pick up native CSS custom props

third_party/polymer/v1_0/components-chromium/iron-a11y-keys-behavior/iron-a11y-keys-behavior-extracted.js

Index: third_party/polymer/v1_0/components-chromium/iron-a11y-keys-behavior/iron-a11y-keys-behavior-extracted.js
diff --git a/third_party/polymer/v1_0/components-chromium/iron-a11y-keys-behavior/iron-a11y-keys-behavior-extracted.js b/third_party/polymer/v1_0/components-chromium/iron-a11y-keys-behavior/iron-a11y-keys-behavior-extracted.js
index 7b534344be0c3d0a416cb1a9027b8124cb6b92bd..ba49601218048a6cd7f584f72ff03d377865ec6e 100644
--- a/third_party/polymer/v1_0/components-chromium/iron-a11y-keys-behavior/iron-a11y-keys-behavior-extracted.js
+++ b/third_party/polymer/v1_0/components-chromium/iron-a11y-keys-behavior/iron-a11y-keys-behavior-extracted.js
@@ -223,12 +223,31 @@
      * and uses an expressive syntax to filter key presses.
      *
      * Use the `keyBindings` prototype property to express what combination of keys
-     * will trigger the event to fire.
+     * will trigger the callback. A key binding has the format
+     * `"KEY+MODIFIER:EVENT": "callback"` (`"KEY": "callback"` or
+     * `"KEY:EVENT": "callback"` are valid as well). Some examples:
      *
-     * Use the `key-event-target` attribute to set up event handlers on a specific
+     *      keyBindings: {
+     *        'space': '_onKeydown', // same as 'space:keydown'
+     *        'shift+tab': '_onKeydown',
+     *        'enter:keypress': '_onKeypress',
+     *        'esc:keyup': '_onKeyup'
+     *      }
+     *
+     * The callback will receive with an event containing the following information in `event.detail`:
+     *
+     *      _onKeydown: function(event) {
+     *        console.log(event.detail.combo); // KEY+MODIFIER, e.g. "shift+tab"
+     *        console.log(event.detail.key); // KEY only, e.g. "tab"
+     *        console.log(event.detail.event); // EVENT, e.g. "keydown"
+     *        console.log(event.detail.keyboardEvent); // the original KeyboardEvent
+     *      }
+     *
+     * Use the `keyEventTarget` attribute to set up event handlers on a specific
      * node.
-     * The `keys-pressed` event will fire when one of the key combinations set with the
-     * `keys` property is pressed.
+     *
+     * See the [demo source code](https://github.com/PolymerElements/iron-a11y-keys-behavior/blob/master/demo/x-key-aware.html)
+     * for an example.
      *
      * @demo demo/index.html
      * @polymerBehavior
@@ -277,6 +296,12 @@
         '_resetKeyEventListeners(keyEventTarget, _boundKeyHandlers)'
       ],
 
+
+      /**
+       * To be used to express what combination of keys  will trigger the relative
+       * callback. e.g. `keyBindings: { 'esc': '_onEscPressed'}`
+       * @type {Object}
+       */
       keyBindings: {},
 
       registered: function() {