Don't delay Firefox startup

lib/filterStorage.js

Index: lib/filterStorage.js
===================================================================
--- a/lib/filterStorage.js
+++ b/lib/filterStorage.js
@@ -23,16 +23,17 @@ Cu.import("resource://gre/modules/Servic
 Cu.import("resource://gre/modules/FileUtils.jsm");
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 
 let {IO} = require("io");
 let {Prefs} = require("prefs");
 let {Filter, ActiveFilter} = require("filterClasses");
 let {Subscription, SpecialSubscription, ExternalSubscription} = require("subscriptionClasses");
 let {FilterNotifier} = require("filterNotifier");
+let {Utils} = require("utils");
 let {TimeLine} = require("timeline");
 
 /**
  * Version number of the filter storage file format.
  * @type Integer
  */
 let formatVersion = 4;
 
@@ -785,19 +786,20 @@ function INIParser()
 {
   this.fileProperties = this.curObj = {};
   this.subscriptions = [];
   this.knownFilters = {__proto__: null};
   this.knownSubscriptions = {__proto__: null};
 }
 INIParser.prototype =
 {
+  linesProcessed: 0,
   subscriptions: null,
   knownFilters: null,
-  knownSubscrptions : null,
+  knownSubscriptions : null,
   wantObj: true,
   fileProperties: null,
   curObj: null,
   curSection: null,
   userFilters: null,
 
   process: function(val)
   {
@@ -872,10 +874,16 @@ INIParser.prototype =
       else if (this.wantObj === false && val)
         this.curObj.push(val.replace(/\\\[/g, "["));
     }
     finally
     {
       Filter.knownFilters = origKnownFilters;
       Subscription.knownSubscriptions = origKnownSubscriptions;
     }
+
+    // Allow events to be processed every now and then.
+    // Note: IO.readFromFile() will deal with the potential reentrance here.
+    this.linesProcessed++;
+    if (this.linesProcessed % 1000 == 0)
+      Utils.yield();
   }
 };