[cros] Temporary whitelist disk I/O on UIThread while store/retrieve signed setting.

chrome/browser/chromeos/login/signed_settings.cc

Index: chrome/browser/chromeos/login/signed_settings.cc
diff --git a/chrome/browser/chromeos/login/signed_settings.cc b/chrome/browser/chromeos/login/signed_settings.cc
index 58bce4bc0d401fb8a25d7792fa3e3289ae44bd76..074d4ad3367a59b9270838b79225632320b78b2f 100644
--- a/chrome/browser/chromeos/login/signed_settings.cc
+++ b/chrome/browser/chromeos/login/signed_settings.cc
@@ -9,6 +9,7 @@
 
 #include "base/ref_counted.h"
 #include "base/stringprintf.h"
+#include "base/threading/thread_restrictions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
@@ -241,7 +242,14 @@ StorePropertyOp::StorePropertyOp(const std::string& name,
 StorePropertyOp::~StorePropertyOp() {}
 
 void StorePropertyOp::Execute() {
-  if (!service_->IsAlreadyOwned()) {
+  bool is_owned = false;
+  {
+    // This should not do blocking IO from the UI thread.
+    // Temporarily allow it for now. http://crbug.com/70097
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    is_owned = service_->IsAlreadyOwned();
+  }
+  if (!is_owned) {
     if (g_browser_process &&
         g_browser_process->local_state() &&
         SignedSettingsTempStorage::Store(name_, value_,
@@ -305,7 +313,14 @@ void RetrievePropertyOp::Execute() {
   // device has been owned and before temp_storage settings are finally
   // persisted into signed settings.
   // In this lapse of time Retrieve loses access to those settings.
-  if (!service_->IsAlreadyOwned()) {
+  bool is_owned = false;
+  {
+    // This should not do blocking IO from the UI thread.
+    // Temporarily allow it for now. http://crbug.com/70097
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    is_owned = service_->IsAlreadyOwned();
+  }
+  if (!is_owned) {
     if (g_browser_process &&
         g_browser_process->local_state() &&
         SignedSettingsTempStorage::Retrieve(