fixes performance issue with Mage.Cookies methods, document.cookie call is not just a string property retrieving - single call can take from 0,03 to 10 milliseconds on various browsers/devices

Author: wujashek

lib/web/mage/cookies.js

@@ -91,17 +91,18 @@
         this.get = function (name) {
             var arg = name + '=',
                 aLength = arg.length,
-                cLength = document.cookie.length,
+                cookie = document.cookie,
+                cLength = cookie.length,
                 i = 0,
                 j = 0;
 
             while (i < cLength) {
                 j = i + aLength;
 
-                if (document.cookie.substring(i, j) === arg) {
+                if (cookie.substring(i, j) === arg) {
                     return this.getCookieVal(j);
                 }
-                i = document.cookie.indexOf(' ', i) + 1;
+                i = cookie.indexOf(' ', i) + 1;
 
                 if (i === 0) {
                     break;
@@ -130,13 +131,14 @@
          * @return {String}
          */
         this.getCookieVal = function (offset) {
-            var endstr = document.cookie.indexOf(';', offset);
+            var cookie = document.cookie,
+                endstr = cookie.indexOf(';', offset);
 
             if (endstr === -1) {
-                endstr = document.cookie.length;
+                endstr = cookie.length;
             }
 
-            return decodeURIComponent(document.cookie.substring(offset, endstr));
+            return decodeURIComponent(cookie.substring(offset, endstr));
         };
 
         return this;