Enable profile switching for standalone App Launcher via the Settings App.

chrome/browser/profiles/profile_manager.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 <set>
 
 #include "chrome/browser/profiles/profile_manager.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 292 matching lines @@
   return relative_profile_dir;
 }
 
 Profile* ProfileManager::GetLastUsedProfile(const FilePath& user_data_dir) {
 #if defined(OS_CHROMEOS)
   // Use default login profile if user has not logged in yet.
   if (!logged_in_)
     return GetDefaultProfile(user_data_dir);
 #endif
 
+  return GetProfile(GetLastUsedProfilePath(user_data_dir));
+}
+
+FilePath ProfileManager::GetLastUsedProfilePath(const FilePath& user_data_dir) {
   FilePath last_used_profile_dir(user_data_dir);
-  std::string last_profile_used;
+  std::string last_used_profile;
   PrefService* local_state = g_browser_process->local_state();
   DCHECK(local_state);
 
-  if (local_state->HasPrefPath(prefs::kProfileLastUsed))
-    last_profile_used = local_state->GetString(prefs::kProfileLastUsed);
-  last_used_profile_dir = last_profile_used.empty() ?
-      last_used_profile_dir.AppendASCII(chrome::kInitialProfile) :
-      last_used_profile_dir.AppendASCII(last_profile_used);
-  return GetProfile(last_used_profile_dir);
+  if (local_state->HasPrefPath(prefs::kProfileLastUsed)) {
+    return last_used_profile_dir.AppendASCII(
+        local_state->GetString(prefs::kProfileLastUsed));
+  }
+
+  return last_used_profile_dir.AppendASCII(chrome::kInitialProfile);
 }
 
 std::vector<Profile*> ProfileManager::GetLastOpenedProfiles(
     const FilePath& user_data_dir) {
   PrefService* local_state = g_browser_process->local_state();
   DCHECK(local_state);
 
   std::vector<Profile*> to_return;
   if (local_state->HasPrefPath(prefs::kProfilesLastActive)) {
     const ListValue* profile_list =
@@ skipping 499 matching lines @@
                                       base::Bind(&OnOpenWindowForNewProfile,
                                                  desktop_type,
                                                  callback),
                                       name,
                                       icon_url,
                                       is_managed);
 }
 
 // static
 void ProfileManager::RegisterPrefs(PrefServiceSimple* prefs) {
+  prefs->RegisterStringPref(prefs::kAppListProfile, "");

[tapted, 2013/01/22 03:01:08]

sorry for not noticing this sooner - but if these changes are going into
profile_manager.cc (and not app_list_controller_win.cc), this and the change in
ScheduleProfileForDeletion will also need an #ifdef guard, unless the #ifdef
guard around prefs::kAppListProfile in pref_names.h/.cc is taken out.

While there's precedent for #if defined OS_IOS/_WIN/_CHROMEOS in
profile_manager.cc already, I'm undecided whether more #ifdefs are a good thing.
I'll defer to someone who's been around longer than me. Perhaps on balance it
makes sense to remove the guard in pref_names.h for clarity, or perhaps having
guards in profile_manager.cc is good additional intrinsic documentation for why
the code is present.

[koz (OOO until 15th September), 2013/01/23 00:07:55]

Good catch. I'll add the #ifdefs for now and see what sail says.

   prefs->RegisterStringPref(prefs::kProfileLastUsed, "");
   prefs->RegisterIntegerPref(prefs::kProfilesNumCreated, 1);
   prefs->RegisterListPref(prefs::kProfilesLastActive);
 }
 
 size_t ProfileManager::GetNumberOfProfiles() {
   return GetProfileInfoCache().GetNumberOfProfiles();
 }
 
 bool ProfileManager::CompareProfilePathAndName(
@@ skipping 132 matching lines @@
     for (size_t i = 0; i < cache.GetNumberOfProfiles(); ++i) {
       FilePath cur_path = cache.GetPathOfProfileAtIndex(i);
       if (cur_path != profile_dir) {
         local_state->SetString(
             prefs::kProfileLastUsed, cur_path.BaseName().MaybeAsASCII());
         break;
       }
     }
   }
 
+  // If the profile the app list uses just got deleted, reset it to the last
+  // used profile.
+  // TODO(koz): Manage the kAppListProfile preference not in this class.
+  std::string app_list_last_profile = local_state->GetString(
+      prefs::kAppListProfile);
+  if (profile_dir.BaseName().MaybeAsASCII() == app_list_last_profile) {
+    local_state->SetString(prefs::kAppListProfile,
+        local_state->GetString(prefs::kProfileLastUsed));
+  }
+
   // TODO(sail): Due to bug 88586 we don't delete the profile instance. Once we
   // start deleting the profile instance we need to close background apps too.
   Profile* profile = GetProfileByPath(profile_dir);
   if (profile) {
     BrowserList::CloseAllBrowsersWithProfile(profile);
 
     // Disable sync for doomed profile.
     if (ProfileSyncServiceFactory::GetInstance()->HasProfileSyncService(
         profile)) {
       ProfileSyncServiceFactory::GetInstance()->GetForProfile(
@@ skipping 66 matching lines @@
 ProfileManager::ProfileInfo::ProfileInfo(
     Profile* profile,
     bool created)
     : profile(profile),
       created(created) {
 }
 
 ProfileManager::ProfileInfo::~ProfileInfo() {
   ProfileDestroyer::DestroyProfileWhenAppropriate(profile.release());
 }