Remove dependency of PrefSyncableService on PrefsTabHelper.

chrome/test/base/testing_profile.cc

Index: chrome/test/base/testing_profile.cc
diff --git a/chrome/test/base/testing_profile.cc b/chrome/test/base/testing_profile.cc
index 77e21651e9400835c300e4922168b2905da84a14..b62b54d0d899f20200756f0e390c4d63a5911830 100644
--- a/chrome/test/base/testing_profile.cc
+++ b/chrome/test/base/testing_profile.cc
@@ -39,6 +39,7 @@
 #include "chrome/browser/profiles/storage_partition_descriptor.h"
 #include "chrome/browser/search_engines/template_url_fetcher_factory.h"
 #include "chrome/browser/sync/glue/sync_start_util.h"
+#include "chrome/browser/ui/prefs/prefs_tab_helper.h"
 #include "chrome/browser/ui/zoom/chrome_zoom_level_prefs.h"
 #include "chrome/browser/web_data_service_factory.h"
 #include "chrome/common/chrome_constants.h"
@@ -744,7 +745,8 @@ void TestingProfile::CreateIncognitoPrefService() {
   DCHECK(!testing_prefs_);
   // Simplified version of ProfileImpl::GetOffTheRecordPrefs(). Note this
   // leaves testing_prefs_ unset.
-  prefs_.reset(original_profile_->prefs_->CreateIncognitoPrefService(NULL));
+  prefs_.reset(original_profile_->prefs_->CreateIncognitoPrefService(
+      NULL, base::Bind(&PrefsTabHelper::InitIncognitoUserPrefStore)));
   user_prefs::UserPrefs::Set(this, prefs_.get());
 }