Policy refresh hits the registry (an I/O operation) on the main thread....

chrome/browser/policy/configuration_policy_provider_win.cc

Index: chrome/browser/policy/configuration_policy_provider_win.cc
===================================================================
--- chrome/browser/policy/configuration_policy_provider_win.cc	(revision 68854)
+++ chrome/browser/policy/configuration_policy_provider_win.cc	(working copy)
@@ -15,6 +15,7 @@
 #include "base/string_piece.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
+#include "base/thread_restrictions.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "base/win/registry.h"
@@ -241,6 +242,10 @@
 
 bool ConfigurationPolicyProviderWin::Provide(
     ConfigurationPolicyStoreInterface* store) {
+  // This function calls GetRegistryPolicy* which hit up the registry. Those
+  // are I/O functions not allowed to be called on the main thread.
+  // http://crbug.com/66453
+  base::ThreadRestrictions::ScopedAllowIO allow_io;

[danno, 2010/12/10 22:19:56]

I don't think this is needed. Provide only gets called on the UI thread early at
startup with the PrefStore is constructed (where you don't need this, right?).
After that, the refresh mechanism already goes to great lengths to make sure
that it gets called on the FILE thread, take a look at PrefValueStore.

   const PolicyDefinitionList* policy_list(policy_definition_list());
   for (const PolicyDefinitionList::Entry* current = policy_list->begin;
        current != policy_list->end; ++current) {