Merge 214426 "Add histograms for session startup enum and number..."

chrome/browser/prefs/session_startup_pref.h

Index: chrome/browser/prefs/session_startup_pref.h
===================================================================
--- chrome/browser/prefs/session_startup_pref.h	(revision 214491)
+++ chrome/browser/prefs/session_startup_pref.h	(working copy)
@@ -39,10 +39,13 @@
 
   // For historical reasons the enum and value registered in the prefs don't
   // line up. These are the values registered in prefs.
+  // The values are also recorded in Settings.StartupPageLoadSettings histogram,
+  // so make sure to update histograms.xml if you change these.
   static const int kPrefValueHomePage = 0;  // Deprecated
   static const int kPrefValueLast = 1;
   static const int kPrefValueURLs = 4;
   static const int kPrefValueNewTab = 5;
+  static const int kPrefValueMax = 6;
 
   static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);