Attempt to fix flaky ChromeOS test timeouts.

chrome/browser/chromeos/preferences_browsertest.cc

 // Copyright 2014 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 <sys/types.h>
 
 #include "ash/shell.h"
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/prefs/pref_service.h"
@@ skipping 122 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(PreferencesTest);
 };
 
 IN_PROC_BROWSER_TEST_F(PreferencesTest, PRE_MultiProfiles) {
   RegisterUser(kTestUsers[0]);
   RegisterUser(kTestUsers[1]);
   chromeos::StartupUtils::MarkOobeCompleted();
 }
 
-// Disabled for flaky timeouts.  https://crbug.com/423077
-IN_PROC_BROWSER_TEST_F(PreferencesTest, DISABLED_MultiProfiles) {
+IN_PROC_BROWSER_TEST_F(PreferencesTest, MultiProfiles) {
   user_manager::UserManager* user_manager = user_manager::UserManager::Get();
 
   // Add first user and init its preferences. Check that corresponding
   // settings has been changed.
   LoginUser(kTestUsers[0]);
   const user_manager::User* user1 = user_manager->FindUser(kTestUsers[0]);
   PrefService* prefs1 =
       ProfileHelper::Get()->GetProfileByUserUnsafe(user1)->GetPrefs();
   SetPrefs(prefs1, false);
   content::RunAllPendingInMessageLoop();
@@ skipping 47 matching lines @@
                      !prefs1->GetBoolean(prefs::kTapToClickEnabled));
   CheckLocalStateCorrespondsToPrefs(prefs1);
 
   // Switch user back.
   user_manager->SwitchActiveUser(kTestUsers[0]);
   CheckSettingsCorrespondToPrefs(prefs1);
   CheckLocalStateCorrespondsToPrefs(prefs1);
 }
 
 }  // namespace chromeos