Remove migration of obsolete value for "session.restore_on_startup".

chrome/common/pref_names.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/common/pref_names.h"
 
 #include "base/basictypes.h"
 #include "chrome/common/features.h"
 #include "chrome/common/pref_font_webkit_names.h"
 
@@ skipping 48 matching lines @@
 // compatibility.
 const char kSessionExitedCleanly[] = "profile.exited_cleanly";
 
 // A string pref whose values is one of the values defined by
 // |ProfileImpl::kPrefExitTypeXXX|. Set to |kPrefExitTypeCrashed| on startup and
 // one of |kPrefExitTypeNormal| or |kPrefExitTypeSessionEnded| during
 // shutdown. Used to determine the exit type the last time the profile was open.
 const char kSessionExitType[] = "profile.exit_type";
 
 // An integer pref. Holds one of several values:
 // 0: (deprecated) open the homepage on startup.

[bartfab (slow), 2015/12/08 10:42:05]

Nit: I think your earlier string ("unused, previously indicated to open the
homepage on startup") is still a better value here. "Deprecated" really means
"deprecated but still working" in Chrome. This value is truly gone.

 // 1: restore the last session.
 // 2: this was used to indicate a specific session should be restored. It is
 //    no longer used, but saved to avoid conflict with old preferences.
 // 3: unused, previously indicated the user wants to restore a saved session.
 // 4: restore the URLs defined in kURLsToRestoreOnStartup.
 // 5: open the New Tab Page on startup.
 const char kRestoreOnStartup[] = "session.restore_on_startup";
 
-// A preference to keep track of whether we have already checked whether we
-// need to migrate the user from kRestoreOnStartup=0 to kRestoreOnStartup=4.
-// We only need to do this check once, on upgrade from m18 or lower to m19 or
-// higher.
-const char kRestoreOnStartupMigrated[] = "session.restore_on_startup_migrated";
-
 // The URLs to restore on startup or when the home button is pressed. The URLs
 // are only restored on startup if kRestoreOnStartup is 4.
 const char kURLsToRestoreOnStartup[] = "session.startup_urls";
 
 // Stores the email address associated with the google account of the custodian
 // of the supervised user, set when the supervised user is created.
 const char kSupervisedUserCustodianEmail[] = "profile.managed.custodian_email";
 
 // Stores the display name associated with the google account of the custodian
 // of the supervised user, updated (if possible) each time the supervised user
@@ skipping 2068 matching lines @@
 // Policy that indicates how to handle animated images.
 const char kAnimationPolicy[] = "settings.a11y.animation_policy";
 #endif
 
 const char kBackgroundTracingLastUpload[] = "background_tracing.last_upload";
 
 const char kAllowDinosaurEasterEgg[] =
     "allow_dinosaur_easter_egg";
 
 }  // namespace prefs