ntp: use web store as default mv tile instead of themes gallery

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';
 
   // We can't pass the currently dragging tile via dataTransfer because of
   // http://crbug.com/31037
   var currentlyDraggingTile = null;
@@ skipping 372 matching lines @@
       this.appendChild(this.content_);
 
       // Div that sets the vertical position of the tile grid.
       this.topMargin_ = this.ownerDocument.createElement('div');
       this.topMargin_.className = 'top-margin';
       this.content_.appendChild(this.topMargin_);
 
       // Div that holds the tiles.
       this.tileGrid_ = this.ownerDocument.createElement('div');
       this.tileGrid_.className = 'tile-grid';
+      this.tileGrid_.style.minWidth = (this.gridValues_.minColCount *
+          this.gridValues_.minTileWidth) + 'px';
       this.content_.appendChild(this.tileGrid_);
 
       // Ordered list of our tiles.
       this.tileElements_ = this.tileGrid_.getElementsByClassName('tile real');
 
       // These are properties used in updateTopMargin.
       this.animatedTopMarginPx_ = 0;
       this.topMarginPx_ = 0;
 
       this.eventTracker = new EventTracker();
@@ skipping 590 matching lines @@
      */
     tileMoved: function(draggedTile) {
     },
   };
 
   return {
     getCurrentlyDraggingTile: getCurrentlyDraggingTile,
     TilePage: TilePage,
   };
 });