Roll Polymer to 1.3.1

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

 /**
 Polymer.IronFitBehavior fits an element in another element using `max-height` and `max-width`, and
 optionally centers it in the window or another element.
 
 The element will only be sized and/or positioned if it has not already been sized and/or positioned
 by CSS.
 
 CSS properties               | Action
 -----------------------------|-------------------------------------------
 `position` set               | Element is not centered horizontally or vertically
@@ skipping 139 matching lines @@
           left: parseInt(target.marginLeft, 10) || 0
         }
       };
     },
 
     /**
      * Resets the target element's position and size constraints, and clear
      * the memoized data.
      */
     resetFit: function() {
+      if (!this._fitInfo || !this._fitInfo.sizedBy.width) {
+        this.sizingTarget.style.maxWidth = '';
+      }
       if (!this._fitInfo || !this._fitInfo.sizedBy.height) {
         this.sizingTarget.style.maxHeight = '';
-        this.style.top = this._fitInfo ? this._fitInfo.inlineStyle.top : '';
       }
-      if (!this._fitInfo || !this._fitInfo.sizedBy.width) {
-        this.sizingTarget.style.maxWidth = '';
-        this.style.left = this._fitInfo ? this._fitInfo.inlineStyle.left : '';
-      }
+      this.style.top = this._fitInfo ? this._fitInfo.inlineStyle.top : '';
+      this.style.left = this._fitInfo ? this._fitInfo.inlineStyle.left : '';
       if (this._fitInfo) {
         this.style.position = this._fitInfo.positionedBy.css;
       }
       this._fitInfo = null;
     },
 
     /**
      * Equivalent to calling `resetFit()` and `fit()`. Useful to call this after the element,
      * the window, or the `fitInfo` element has been resized.
      */
@@ skipping 40 matching lines @@
       var offsetExtent = 'offset' + extent;
       var sizingOffset = this[offsetExtent] - this.sizingTarget[offsetExtent];
       this.sizingTarget.style['max' + extent] = (max - margin - offset - sizingOffset) + 'px';
     },
 
     /**
      * Centers horizontally and vertically if not already positioned. This also sets
      * `position:fixed`.
      */
     center: function() {
-      if (!this._fitInfo.positionedBy.vertically || !this._fitInfo.positionedBy.horizontally) {
-        // need position:fixed to center
-        this.style.position = 'fixed';
+      var positionedBy = this._fitInfo.positionedBy;
+      if (positionedBy.vertically && positionedBy.horizontally) {
+        // Already positioned.
+        return;
       }
-      if (!this._fitInfo.positionedBy.vertically) {
-        var top = (this._fitHeight - this.offsetHeight) / 2 + this._fitTop;
-        top -= this._fitInfo.margin.top;
+      // Need position:fixed to center
+      this.style.position = 'fixed';
+      // Take into account the offset caused by parents that create stacking
+      // contexts (e.g. with transform: translate3d). Translate to 0,0 and
+      // measure the bounding rect.
+      if (!positionedBy.vertically) {
+        this.style.top = '0px';
+      }
+      if (!positionedBy.horizontally) {
+        this.style.left = '0px';
+      }
+      // It will take in consideration margins and transforms
+      var rect = this.getBoundingClientRect();
+      if (!positionedBy.vertically) {
+        var top = this._fitTop - rect.top + (this._fitHeight - rect.height) / 2;
         this.style.top = top + 'px';
       }
-      if (!this._fitInfo.positionedBy.horizontally) {
-        var left = (this._fitWidth - this.offsetWidth) / 2 + this._fitLeft;
-        left -= this._fitInfo.margin.left;
+      if (!positionedBy.horizontally) {
+        var left = this._fitLeft - rect.left + (this._fitWidth - rect.width) / 2;
         this.style.left = left + 'px';
       }
     }
 
   };