[Form] Remove choice or choice_list requirement as the following conditions already check enough and this condition prevents empty select forms (populated by ajax for example)

src/Symfony/Component/Form/Extension/Core/Type/ChoiceType.php

@@ -31,10 +31,6 @@ class ChoiceType extends AbstractType
      */
     public function buildForm(FormBuilder $builder, array $options)
     {
-        if (!$options['choices'] && !$options['choice_list']) {
-            throw new FormException('Either the option "choices" or "choice_list" is required');
-        }
-
         if ($options['choice_list'] && !$options['choice_list'] instanceof ChoiceListInterface) {
             throw new FormException('The "choice_list" must be an instance of "Symfony\Component\Form\Extension\Core\ChoiceList\ChoiceListInterface".');
         }

tests/Symfony/Tests/Component/Form/Extension/Core/Type/ChoiceTypeTest.php

@@ -303,14 +303,6 @@ class ChoiceTypeTest extends TypeTestCase
         $this->assertEquals(array('0', '1'), $form->getClientData());
     }
 
-    /**
-     * @expectedException Symfony\Component\Form\Exception\FormException
-     */
-    public function testRequiresChoicesOrChoiceListOption()
-    {
-        $this->factory->create('choice', 'name');
-    }
-
     public function testPassRequiredToView()
     {
         $form = $this->factory->create('choice', null, array(