Create a secondary file thread, FILE_USER_BLOCKING...

chrome/browser/chrome_browser_main.cc

Index: chrome/browser/chrome_browser_main.cc
===================================================================
--- chrome/browser/chrome_browser_main.cc	(revision 106339)
+++ chrome/browser/chrome_browser_main.cc	(working copy)
@@ -315,6 +315,7 @@
   process->file_thread();
   process->process_launcher_thread();
   process->cache_thread();
+  process->appcache_thread();

[rvargas (doing something else), 2011/10/21 19:46:17]

Do you mind creating this thread before the cache thread. I'd prefer to keep the
cache and io thread together so that they are easier to identify on crash dumps.

[michaeln, 2011/10/21 19:52:12]

will do (ditto other necessary places)

   process->io_thread();
 #if defined(OS_CHROMEOS)
   process->web_socket_proxy_thread();