Update bower.json for Polymer elements and add PRESUBMIT.py

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

 
 
  /** 
  * `iron-range-behavior` provides the behavior for something with a minimum to maximum range.
  *
  * @demo demo/index.html
  * @polymerBehavior 
  */
  Polymer.IronRangeBehavior = {
 
@@ skipping 53 matching lines @@
 
   _calcRatio: function(value) {
     return (this._clampValue(value) - this.min) / (this.max - this.min);
   },
 
   _clampValue: function(value) {
     return Math.min(this.max, Math.max(this.min, this._calcStep(value)));
   },
 
   _calcStep: function(value) {
+   /**
+    * if we calculate the step using
+    * `Math.round(value / step) * step` we may hit a precision point issue 
+    * eg. 0.1 * 0.2 =  0.020000000000000004
+    * http://docs.oracle.com/cd/E19957-01/806-3568/ncg_goldberg.html
+    *
+    * as a work around we can divide by the reciprocal of `step`
+    */
     return this.step ? (Math.round(value / this.step) / (1 / this.step)) : value;
   },
 
   _validateValue: function() {
     var v = this._clampValue(this.value);
     this.value = this.oldValue = isNaN(v) ? this.oldValue : v;
     return this.value !== v;
   },
 
   _update: function() {
     this._validateValue();
     this._setRatio(this._calcRatio(this.value) * 100);
   }
 
 };