Make extensions DSE persistent in browser prefs

chrome/browser/prefs/session_startup_pref.cc

Index: chrome/browser/prefs/session_startup_pref.cc
diff --git a/chrome/browser/prefs/session_startup_pref.cc b/chrome/browser/prefs/session_startup_pref.cc
index 7bcf8d03f0d69fdc2ecf524846bcb464e15ab352..345ce21c1b4935582c71fafc83968b858dd428fb 100644
--- a/chrome/browser/prefs/session_startup_pref.cc
+++ b/chrome/browser/prefs/session_startup_pref.cc
@@ -41,6 +41,11 @@ void URLListToPref(const base::ListValue* url_list, SessionStartupPref* pref) {
 
 }  // namespace
 
+const int SessionStartupPref::kPrefValueLast;
+const int SessionStartupPref::kPrefValueURLs;
+const int SessionStartupPref::kPrefValueNewTab;
+const int SessionStartupPref::kPrefValueMax;
+
 // static
 void SessionStartupPref::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {