Move ProxyConfigService construction onto the IO thread.

chrome/browser/profiles/profile_io_data.h

Index: chrome/browser/profiles/profile_io_data.h
diff --git a/chrome/browser/profiles/profile_io_data.h b/chrome/browser/profiles/profile_io_data.h
index 65a94f6b17a34114cf390b1a153695cc3d7d67ca..e255875caf8da9b4e4b0a889c5d40134d8557c72 100644
--- a/chrome/browser/profiles/profile_io_data.h
+++ b/chrome/browser/profiles/profile_io_data.h
@@ -206,10 +206,8 @@ class ProfileIOData {
     scoped_ptr<net::URLRequestJobFactory::Interceptor>
         protocol_handler_interceptor;
 
-    // We need to initialize the ProxyConfigService from the UI thread
-    // because on linux it relies on initializing things through gconf,
-    // and needs to be on the main thread.
-    scoped_ptr<net::ProxyConfigService> proxy_config_service;
+    // Used on the UI thread to return a pointer to the Profile.

[willchan no longer on Chromium, 2012/10/19 18:06:36]

This is too powerful. We should try to keep the scope narrow. The Profile object
contains too many dependencies. Please restructure the callback so it doesn't
return a raw Profile*, but only exactly what you need.

I am still looking, but you should make sure to handle shutdown properly. What
happens when this gets posted from the IO thread to the UI thread while the
profile (let's say an incognito profile) is being destroyed? Do we get a use
after free? Be very very careful :)

[pauljensen, 2012/10/19 22:34:28]

Sorry, I was just copying how ChromeCookieMonsterDelegate gets a pointer to the
Profile.  I could instead replace it with a Callback that just takes a
ChromeProxyConfigService argument and doesn't return anything.
It uses GetProfileOnUI() which checks with IsValidProfile() to make sure its
still alive.

+    base::Callback<Profile*(void)> profile_getter;
     // The profile this struct was populated from. It's passed as a void* to
     // ensure it's not accidently used on the IO thread. Before using it on the
     // UI thread, call ProfileManager::IsValidProfile to ensure it's alive.