Remove PrefServiceSimple, replacing it with PrefService and PrefRegistrySimple.

chrome/browser/about_flags_unittest.cc

Index: chrome/browser/about_flags_unittest.cc
diff --git a/chrome/browser/about_flags_unittest.cc b/chrome/browser/about_flags_unittest.cc
index cff2597aade89476c032d6c726db880e42258f66..56336e60d8957decd8126960506f35dbfb86e30a 100644
--- a/chrome/browser/about_flags_unittest.cc
+++ b/chrome/browser/about_flags_unittest.cc
@@ -86,7 +86,7 @@ static Experiment kExperiments[] = {
 class AboutFlagsTest : public ::testing::Test {
  protected:
   AboutFlagsTest() {
-    prefs_.RegisterListPref(prefs::kEnabledLabsExperiments);
+    prefs_.registrar()->RegisterListPref(prefs::kEnabledLabsExperiments);
     testing::ClearState();
   }