Switch guest profile from forced-incognito to UI mods like ChromeOS.

chrome/browser/profiles/profile_manager.cc

Index: chrome/browser/profiles/profile_manager.cc
diff --git a/chrome/browser/profiles/profile_manager.cc b/chrome/browser/profiles/profile_manager.cc
index ebfe635a8d4569882a55c6c28509b3391b5650c5..9029acbcbec3d3c60e7a77459e3cf12a8fabb1d0 100644
--- a/chrome/browser/profiles/profile_manager.cc
+++ b/chrome/browser/profiles/profile_manager.cc
@@ -1108,22 +1108,22 @@ void ProfileManager::AddProfileToCache(Profile* profile) {
 
 void ProfileManager::SetGuestProfilePrefs(Profile* profile) {
   IncognitoModePrefs::SetAvailability(profile->GetPrefs(),
-                                      IncognitoModePrefs::FORCED);
+                                      IncognitoModePrefs::ENABLED);

[noms (inactive), 2014/02/14 19:28:10]

I think this is the default behaviour, so you don't need to set the pref
explicitly anymore. 

[bcwhite, 2014/02/14 19:46:36]

It has to be present to switch existing Guest profiles to the new state. 
Otherwise they will remain in forced-incognito.  I'll add a comment that it can
be removed later.

   profile->GetPrefs()->SetBoolean(prefs::kShowBookmarkBar, false);

[noms (inactive), 2014/02/14 19:28:10]

Is this still needed? At the moment you can bring it up with the accelerator, so
it's only hiding it, not disabling it.

[bcwhite, 2014/02/14 19:46:36]

Done.

 }
 
 bool ProfileManager::ShouldGoOffTheRecord(Profile* profile) {
-  bool go_off_the_record = false;
+  if (profile->IsGuestSession())
+    return true;
 #if defined(OS_CHROMEOS)
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  if (command_line.HasSwitch(chromeos::switches::kGuestSession) ||
-      (profile->GetPath().BaseName().value() == chrome::kInitialProfile &&
-       (!command_line.HasSwitch(switches::kTestType) ||
-       command_line.HasSwitch(chromeos::switches::kLoginProfile)))) {
-    go_off_the_record = true;
+  if (profile->GetPath().BaseName().value() == chrome::kInitialProfile &&
+      (!command_line.HasSwitch(switches::kTestType) ||
+      command_line.HasSwitch(chromeos::switches::kLoginProfile))) {
+    return true;
   }
 #endif
-  return go_off_the_record;
+  return false;

[noms (inactive), 2014/02/14 19:28:10]

If you move the ifdef to the top, you can just return profile->IsGuestSession(),
rather than returning twice.

[bcwhite, 2014/02/14 19:46:36]

Could...  but I think the style of testing various conditions and returning is a
better choice here.

 }
 
 void ProfileManager::RunCallbacks(const std::vector<CreateCallback>& callbacks,