Move thread checking from autofill_country.cc to browser_process_impl.cc

chrome/browser/browser_process_impl.cc

Index: chrome/browser/browser_process_impl.cc
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index f3e5f0be7bb7b52be0f5d5dd865c364d4c991b44..05b1ac49fe16434d0acc83448362c3c5f6cc6a20 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -531,11 +531,13 @@ IntranetRedirectDetector* BrowserProcessImpl::intranet_redirect_detector() {
 }
 
 const std::string& BrowserProcessImpl::GetApplicationLocale() {
+  DCHECK(CalledOnValidThread());
   DCHECK(!locale_.empty());
   return locale_;
 }
 
 void BrowserProcessImpl::SetApplicationLocale(const std::string& locale) {
+  DCHECK(CalledOnValidThread());
   locale_ = locale;
   extension_l10n_util::SetProcessLocale(locale);
 }