Roll third_party/polymer.

third_party/polymer/v1_0/components-chromium/paper-slider/paper-slider-extracted.js

 Polymer({
       is: 'paper-slider',
 
       behaviors: [
         Polymer.IronA11yKeysBehavior,
         Polymer.IronFormElementBehavior,
         Polymer.PaperInkyFocusBehavior,
         Polymer.IronRangeBehavior
       ],
 
@@ skipping 260 matching lines @@
         if (prevRatio === this.ratio) {
           this._setTransiting(false);
         }
 
         this.async(function() {
           this.fire('change');
         });
 
         // cancel selection
         event.preventDefault();
+
+        // set the focus manually because we will called prevent default
+        this.focus();
       },
 
       _knobTransitionEnd: function(event) {
         if (event.target === this.$.sliderKnob) {
           this._setTransiting(false);
         }
       },
 
       _maxMarkersChanged: function(maxMarkers) {
         if (!this.snaps) {
           this._setMarkers([]);
         }
-        var steps = Math.floor((this.max - this.min) / this.step);
+        var steps = Math.round((this.max - this.min) / this.step);
         if (steps > maxMarkers) {
           steps = maxMarkers;
         }
         this._setMarkers(new Array(steps));
       },
 
       _mergeClasses: function(classes) {
         return Object.keys(classes).filter(
           function(className) {
             return classes[className];
@@ skipping 53 matching lines @@
       // Hide the ripple when user is not interacting with keyboard.
       // This behavior is different from other ripple-y controls, but is
       // according to spec: https://www.google.com/design/spec/components/sliders.html
       _focusedChanged: function(receivedFocusFromKeyboard) {
         if (receivedFocusFromKeyboard) {
           this.ensureRipple();
         }
         if (this.hasRipple()) {
           // note, ripple must be un-hidden prior to setting `holdDown`
           if (receivedFocusFromKeyboard) {
-            this._ripple.removeAttribute('hidden');
+            this._ripple.style.display = '';
           } else {
-            this._ripple.setAttribute('hidden', '');
+            this._ripple.style.display = 'none';
           }
           this._ripple.holdDown = receivedFocusFromKeyboard;
         }
       }
     });
 
     /**
      * Fired when the slider's value changes.
      *
      * @event value-change
      */
 
     /**
      * Fired when the slider's immediateValue changes.
      *
      * @event immediate-value-change
      */
 
     /**
      * Fired when the slider's value changes due to user interaction.
      *
      * Changes to the slider's value due to changes in an underlying
      * bound variable will not trigger this event.
      *
      * @event change
      */