Bug 499601: A lot of 'leaked URLs' when Fennec is finished, r=mfinkle

mobile/chrome/content/CanvasBrowser.js

@@ -156,6 +156,9 @@ CanvasBrowser.prototype = {
 
     this._contentDOMWindowUtils = null;
     
+    if (!browser)
+      return;
+
     browser.setAttribute("type", "content-primary");
     if (!skipZoom)
       browser.docShell.isOffScreenBrowser = true;

mobile/chrome/content/browser.js

@@ -251,6 +251,8 @@ var Browser = {
   },
 
   shutdown: function() {
+    this._canvasBrowser.setCurrentBrowser(null);
+    
     BrowserUI.uninit();
 
     var os = Cc["@mozilla.org/observer-service;1"].getService(Ci.nsIObserverService);