Merge pull request #1549 from mozilla/issue1546-kpi-storage

@ozten - Nice work on the cleanup.  What if we created one logger that we could use to universally log these sorts of things?  If we consolidated all of the logging into one module, we could add/remove/turn on or off functionality we use for logging.

For the removed "delete" statement, it is safer to use localStorage.removeItem.  I forgot which browser was giving us problems with that, in the end I wrote a load of unit tests and did a browser comparison blog post (http://www.shanetomlinson.com/2012/localstorage-bugs-inconsistent-removeitem-delete/) - the trouble with delete came from IE8.  

In IE8, if the item you are trying to call delete on is not already in localStorage, it will throw an exception.  IE8 does not have this problem with localStorage.removeItem.

r+ - Merging.

close #1546

resources/static/shared/storage.js

@@ -2,6 +2,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
+/*globals BrowserID: true, console: true */
+
 BrowserID.Storage = (function() {
   "use strict";
 
@@ -25,6 +27,11 @@ BrowserID.Storage = (function() {
     };
   }
 
+  // temporary, replace with helpers.log if storage uses elog long term...
+  function elog (msg) {
+    if (window.console && console.error) console.error(msg);
+  }
+
   function prepareDeps() {
     if (!jwcrypto) {
       jwcrypto = require("./jwcrypto");
@@ -271,7 +278,7 @@ BrowserID.Storage = (function() {
         lastUpdated = Date.parse(userInfo.updated);
 
         if (!validState(currentState)) throw "corrupt/outdated";
-        if (NaN === lastUpdated) throw "corrupt/outdated";
+        if (isNaN(lastUpdated)) throw "corrupt/outdated";
       }
     } catch(e) {
       currentState = undefined;
@@ -409,7 +416,7 @@ BrowserID.Storage = (function() {
     try {
       return storage.interactionData ? JSON.parse(storage.interactionData)[0] : {};
     } catch(e) {
-      if (window.console && console.error) console.error(e);
+      elog(e);
       return {};
     }
   }
@@ -420,7 +427,7 @@ BrowserID.Storage = (function() {
       id = JSON.parse(storage.interactionData);
       id[0] = data;
     } catch(e) {
-      if (window.console && console.error) console.error(e);
+      elog(e);
       id = [ data ];
     }
     storage.interactionData = JSON.stringify(id);
@@ -439,8 +446,8 @@ BrowserID.Storage = (function() {
     try {
       storage.interactionData = JSON.stringify([]);
     } catch(e) {
-      delete storage.interactionData;
-      if (window.console && console.error) console.error(e);
+      storage.removeItem("interactionData");
+      elog(e);
     }
   }