Fix a crash due to UserScriptListener unregistering notifications on the wrong

chrome/browser/extensions/user_script_listener.h

Index: chrome/browser/extensions/user_script_listener.h
diff --git a/chrome/browser/extensions/user_script_listener.h b/chrome/browser/extensions/user_script_listener.h
index f24bd05ccccd5ec4957325e7d85e2a7f0b885682..f10240be816ffd7ec7bbcfd423390bff4d343b07 100644
--- a/chrome/browser/extensions/user_script_listener.h
+++ b/chrome/browser/extensions/user_script_listener.h
@@ -30,6 +30,10 @@ class UserScriptListener
  public:
   explicit UserScriptListener(ResourceQueue* resource_queue);
 
+  // Call this to do necessary cleanup on the main thread before the object
+  // is deleted.
+  void ShutdownMainThread();

[Paweł Hajdan Jr., 2010/03/18 07:47:54]

The object is constructed on the UI thread, and currently the dtor is empty. How
about using ChromeThread::DeleteOnUIThread, and doing the cleanup in the dtor?

[Matt Perry, 2010/03/18 18:00:55]

That doesn't work, because the object is deleted so late in the shutdown process
that the UI loop never has a chance to pump messages. We would just leak the
object.

+
   // ResourceQueueDelegate:
   virtual bool ShouldDelayRequest(
       URLRequest* request,