Multiprofile: switch to newly added user to the session

This CL remember pending user switch and do it as soon as profile
ready. From UI perspective this look very smooth because profile loading
is actually fast so previous desktop is not shown. But if it will be
a problem on slow device we may need to stay on add user screen a bit longer.

BUG=333879
TEST=manual
R=nkostylev@chromium.org

Review URL: https://codereview.chromium.org/246253009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266239 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 22 insertions, 14 deletions

diff --git a/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc b/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc
index 858172b..a626517c4 100644
--- a/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc
+++ b/chrome/browser/chromeos/file_manager/file_manager_browsertest.cc
@@ -915,9 +915,6 @@ class MultiProfileFileManagerBrowserTest : public FileManagerBrowserTestBase {
     const TestAccountInfo& info = kTestAccounts[PRIMARY_ACCOUNT_INDEX];
 
     AddUser(info, true);
-    chromeos::UserManager* const user_manager = chromeos::UserManager::Get();
-    if (user_manager->GetActiveUser() != user_manager->FindUser(info.email))
-      chromeos::UserManager::Get()->SwitchActiveUser(info.email);
     FileManagerBrowserTestBase::SetUpOnMainThread();
   }
 
diff --git a/chrome/browser/chromeos/login/user_manager_impl.cc b/chrome/browser/chromeos/login/user_manager_impl.cc
index 9fcd332..7f27162 100644
--- a/chrome/browser/chromeos/login/user_manager_impl.cc
+++ b/chrome/browser/chromeos/login/user_manager_impl.cc
@@ -424,9 +424,9 @@ void UserManagerImpl::UserLoggedIn(const std::string& user_id,
     lru_logged_in_users_.push_back(user);
     // Reset the new user flag if the user already exists.
     is_current_user_new_ = false;
-    // Set active user wallpaper back.
-    WallpaperManager::Get()->SetUserWallpaperNow(active_user_->email());
     NotifyUserAddedToSession(user);
+    // Remember that we need to switch to this user as soon as profile ready.
+    pending_user_switch_ = user_id;
     return;
   }
 
@@ -971,7 +971,18 @@ void UserManagerImpl::Observe(int type,
       User* user = GetUserByProfile(profile);
       if (user != NULL)
         user->set_profile_is_created();
-
+      // If there is pending user switch, do it now.
+      if (!pending_user_switch_.empty()) {
+        // Call SwitchActiveUser async because otherwise it may cause
+        // ProfileManager::GetProfile before the profile gets registered
+        // in ProfileManager. It happens in case of sync profile load when
+        // NOTIFICATION_PROFILE_CREATED is called synchronously.
+        base::MessageLoop::current()->PostTask(FROM_HERE,
+          base::Bind(&UserManagerImpl::SwitchActiveUser,
+                     base::Unretained(this),
+                     pending_user_switch_));
+        pending_user_switch_.clear();
+      }
       break;
     }
     default:
diff --git a/chrome/browser/chromeos/login/user_manager_impl.h b/chrome/browser/chromeos/login/user_manager_impl.h
index ef63d1a..1ec2c2e 100644
--- a/chrome/browser/chromeos/login/user_manager_impl.h
+++ b/chrome/browser/chromeos/login/user_manager_impl.h
@@ -483,6 +483,10 @@ class UserManagerImpl
   scoped_ptr<policy::CloudExternalDataPolicyObserver>
       wallpaper_policy_observer_;
 
+  // ID of the user just added to the session that needs to be activated
+  // as soon as user's profile is loaded.
+  std::string pending_user_switch_;
+
   DISALLOW_COPY_AND_ASSIGN(UserManagerImpl);
 };
 
diff --git a/chrome/browser/chromeos/preferences_browsertest.cc b/chrome/browser/chromeos/preferences_browsertest.cc
index fe3fb00..b8a5267 100644
--- a/chrome/browser/chromeos/preferences_browsertest.cc
+++ b/chrome/browser/chromeos/preferences_browsertest.cc
@@ -153,19 +153,15 @@ IN_PROC_BROWSER_TEST_F(PreferencesTest, MultiProfiles) {
   // Add second user and init its prefs with different values.
   UserAddingScreen::Get()->Start();
   content::RunAllPendingInMessageLoop();
+  DisableAnimations();
   AddUser(kTestUsers[1]);
-  EXPECT_TRUE(user1->is_active());
+  content::RunAllPendingInMessageLoop();
   const User* user2 = user_manager->FindUser(kTestUsers[1]);
+  EXPECT_TRUE(user2->is_active());
   PrefService* prefs2 = user_manager->GetProfileByUser(user2)->GetPrefs();
   SetPrefs(prefs2, true);
 
-  // First user is still active, so settings was not changed.
-  EXPECT_TRUE(user1->is_active());
-  CheckSettingsCorrespondToPrefs(prefs1);
-
-  // Switch user and check that settings was changed accordingly.
-  DisableAnimations();
-  user_manager->SwitchActiveUser(kTestUsers[1]);
+  // Check that settings were changed accordingly.
   EXPECT_TRUE(user2->is_active());
   CheckSettingsCorrespondToPrefs(prefs2);