Do the ReloadLocaleResources() call on the IO thread to avoid synchronization issues.

chrome/test/base/ui_test_utils.cc

Index: chrome/test/base/ui_test_utils.cc
diff --git a/chrome/test/base/ui_test_utils.cc b/chrome/test/base/ui_test_utils.cc
index 779c1a9bf9b11747f87196874b5793938ad0d9e3..2460bd7255650a9a02643fda1b833935f5e47014 100644
--- a/chrome/test/base/ui_test_utils.cc
+++ b/chrome/test/base/ui_test_utils.cc
@@ -23,6 +23,7 @@
 #include "base/rand_util.h"
 #include "base/string_number_conversions.h"
 #include "base/test/test_timeouts.h"
+#include "base/threading/platform_thread.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
@@ -378,6 +379,13 @@ Browser* WaitForBrowserNotInSet(std::set<Browser*> excluded_browsers) {
   return new_browser;
 }
 
+void WaitEventSignaled(base::WaitableEvent* event) {
+  while (!event->IsSignaled()) {
+    base::PlatformThread::YieldCurrentThread();
+    RunAllPendingInMessageLoop();
+  }
+}
+
 void OpenURLOffTheRecord(Profile* profile, const GURL& url) {
   Browser::OpenURLOffTheRecord(profile, url);
   Browser* browser = browser::FindTabbedBrowser(