Make the default startup pref to be NTP also on Mac.

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 d63767dd691698df4aac0ffa0b4edb04ad4ee6dc..bbe96c9e5b725b9044b9d6767d89dfeb3e957cbd 100644
--- a/chrome/browser/prefs/session_startup_pref.cc
+++ b/chrome/browser/prefs/session_startup_pref.cc
@@ -7,6 +7,7 @@
 #include <string>
 
 #include "base/values.h"
+#include "base/version.h"
 #include "chrome/browser/net/url_fixer_upper.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prefs/scoped_user_pref_update.h"
@@ -72,18 +73,10 @@ void SessionStartupPref::RegisterUserPrefs(PrefService* prefs) {
 // static
 SessionStartupPref::Type SessionStartupPref::GetDefaultStartupType() {
 #if defined(OS_CHROMEOS)
-  SessionStartupPref::Type type = SessionStartupPref::LAST;
+  return SessionStartupPref::LAST;
 #else
-  SessionStartupPref::Type type = SessionStartupPref::DEFAULT;
+  return SessionStartupPref::DEFAULT;
 #endif
-
-#if defined(OS_MACOSX)
-  // Use Lion's system preference, if it is set.
-  if (restore_utils::IsWindowRestoreEnabled())
-    type = SessionStartupPref::LAST;
-#endif
-
-  return type;
 }
 
 // static
@@ -129,6 +122,11 @@ SessionStartupPref SessionStartupPref::GetStartupPref(PrefService* prefs) {
 
   MigrateIfNecessary(prefs);
 
+#if defined(OS_MACOSX)
+  if (restore_utils::IsWindowRestoreEnabled())
+    MigrateMacDefaultPrefIfNecessary(prefs);
+#endif
+
   SessionStartupPref pref(
       PrefValueToType(prefs->GetInteger(prefs::kRestoreOnStartup)));
 
@@ -189,6 +187,18 @@ void SessionStartupPref::MigrateIfNecessary(PrefService* prefs) {
 }
 
 // static
+void SessionStartupPref::MigrateMacDefaultPrefIfNecessary(PrefService* prefs) {
+  DCHECK(prefs);
+  // The default startup pref used to be LAST, now it is DEFAULT. Don't change
+  // the setting for existing profiles (even if the user has never changed it),
+  // but make new profiles default to DEFAULT.
+  bool old_profile_version = Version(prefs->GetString(
+      prefs::kProfileCreatedByVersion)).IsOlderThan("21.0.1180.0");
+  if (old_profile_version && TypeIsDefault(prefs))
+    prefs->SetInteger(prefs::kRestoreOnStartup, kPrefValueLast);

[Joao da Silva, 2012/06/19 15:23:00]

kPrevValueLast might not be the right value here, depending on the Lion system
setting. If restore_utils::IsWindowRestoreEnabled() is false, then this should
be kPrefValueNewTab.

[marja, 2012/06/19 15:24:48]

This code only gets executed if restore_utils::IsWindowRestoreEnabled() is true
(see above).

+}
+
+// static
 bool SessionStartupPref::TypeIsManaged(PrefService* prefs) {
   DCHECK(prefs);
   const PrefService::Preference* pref_restore =