ntp4: Fix a couple small visual glitches with tile dragging.

chrome/browser/resources/ntp4/tile_page.js

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 cr.define('ntp4', function() {
   'use strict';
 
   /**
    * Creates a new Tileobject. Tiles wrap content on a TilePage, providing
    * some styling and drag functionality.
@@ skipping 81 matching lines @@
 
       this.onDragMove_(e);
     },
 
     /**
      * The handler for drag events fired on |this|.
      * @param {Event} e The event for the drag.
      * @private
      */
     onDragMove_: function(e) {
+      if (e.view != window || (e.pageX == 0 && e.pageY == 0)) {
+        // attribute hidden seems to be overridden by display.
+        this.dragClone.classList.add('hidden');
+        return;
+      }
+
+      this.dragClone.classList.remove('hidden');
       this.dragClone.style.left = (e.pageX - this.dragOffsetX) + 'px';
       this.dragClone.style.top = (e.pageY - this.dragOffsetY) + 'px';
     },
 
     /**
      * The handler for dragend events fired on |this|.
      * @param {Event} e The event for the drag.
      * @private
      */
     onDragEnd_: function(e) {
@@ skipping 56 matching lines @@
     hasDoppleganger: function() {
       return !!this.doppleganger_;
     },
 
     /**
      * Called when the drag representation node is done migrating to its final
      * resting spot.
      * @param {Event} e The transition end event.
      */
     onDragCloneTransitionEnd_: function(e) {
-      var clone = this.dragClone;
-      this.dragClone = null;
+      if (e.propertyName == 'left') {
+        var clone = this.dragClone;
+        this.dragClone = null;
 
-      clone.parentNode.removeChild(clone);
-      this.eventTracker.remove(clone, 'webkitTransitionEnd');
-      this.classList.remove('dragging');
+        clone.parentNode.removeChild(clone);
+        this.eventTracker.remove(clone, 'webkitTransitionEnd');
+        this.classList.remove('dragging');
+      }
     }
   };
 
   /**
    * Gives the proportion of the row width that is devoted to a single icon.
    * @param {number} rowTileCount The number of tiles in a row.
    * @return {number} The ratio between icon width and row width.
    */
   function tileWidthFraction(rowTileCount) {
     return rowTileCount +
@@ skipping 628 matching lines @@
       // This should not get called unless there is a non-default
       // implementation.
       assert(false);
     },
   };
 
   return {
     TilePage: TilePage,
   };
 });