OOP PDF - Add support for "zoom" open pdf parameter

chrome/browser/resources/pdf/open_pdf_params_parser.js

 // Copyright 2014 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.
 
 'use strict';
 
 /**
  * Creates a new OpenPDFParamsParser. This parses the open pdf parameters
  * passed in the url to set initial viewport settings for opening the pdf.
  * @param {string} url to be parsed.
  */
 function OpenPDFParamsParser(url) {
   this.url_ = url;
   this.urlParams = {};
   this.parseOpenPDFParams_();
 }
 
 OpenPDFParamsParser.prototype = {
   /**
    * @private
+   * Parse zoom parameter of open PDF parameters. If this
+   * parameter is passed while opening PDF then PDF should be opened
+   * at the specified zoom level.
+   * @param {number} zoom value.
+   */
+  parseZoomParam_: function(paramValue) {
+    var paramValueSplit = paramValue.split(',');
+    if ((paramValueSplit.length != 1) && (paramValueSplit.length != 3))
+      return;
+
+    // User scale of 100 means zoom value of 100% i.e. zoom factor of 1.0.
+    var zoomFactor = parseFloat(paramValueSplit[0]) / 100;
+    if (isNaN(zoomFactor))
+      return;
+
+    // Handle #zoom=scale.
+    if (paramValueSplit.length == 1) {
+      this.urlParams['zoom'] = zoomFactor;
+      return;
+    }
+
+    // Handle #zoom=scale,left,top.
+    var position = {x: parseFloat(paramValueSplit[1]),
+                    y: parseFloat(paramValueSplit[2])};
+    this.urlParams['position'] = position;
+    this.urlParams['zoom'] = zoomFactor;
+  },
+
+  /**
+   * @private
    * Parse open PDF parameters. These parameters are mentioned in the url
    * and specify actions to be performed when opening pdf files.
    * See http://www.adobe.com/content/dam/Adobe/en/devnet/acrobat/
    * pdfs/pdf_open_parameters.pdf for details.
    */
   parseOpenPDFParams_: function() {
     var originalUrl = this.url_;
     var paramIndex = originalUrl.search('#');
     if (paramIndex == -1)
       return;
 
     var paramTokens = originalUrl.substring(paramIndex + 1).split('&');
     var paramsDictionary = {};
     for (var i = 0; i < paramTokens.length; ++i) {
       var keyValueSplit = paramTokens[i].split('=');
       if (keyValueSplit.length != 2)
         continue;
       paramsDictionary[keyValueSplit[0]] = keyValueSplit[1];
     }
 
     if ('page' in paramsDictionary) {
       // |pageNumber| is 1-based, but goToPage() take a zero-based page number.
       var pageNumber = parseInt(paramsDictionary['page']);
       if (!isNaN(pageNumber))
         this.urlParams['page'] = pageNumber - 1;
     }
+
+    if ('zoom' in paramsDictionary)
+      this.parseZoomParam_(paramsDictionary['zoom']);
   }
 };