reverted:
--- b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/UriWidget.php
+++ a/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/UriWidget.php
@@ -1,86 +0,0 @@
-<?php
-
-/**
- * @file
- * Contains \Drupal\Core\Field\Plugin\Field\FieldWidget\UriWidget.
- */
-
-namespace Drupal\Core\Field\Plugin\Field\FieldWidget;
-
-use Drupal\Core\Field\FieldItemListInterface;
-use Drupal\Core\Field\WidgetBase;
-
-/**
- * Plugin implementation of the 'uri' widget.
- *
- * @FieldWidget(
- *   id = "uri",
- *   label = @Translation("Uri field"),
- *   field_types = {
- *     "uri"
- *   }
- * )
- */
-class UriWidget extends WidgetBase {
-
-  /**
-   * {@inheritdoc}
-   */
-  public static function defaultSettings() {
-    return array(
-      'size' => 60,
-      'placeholder' => '',
-    ) + parent::defaultSettings();
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function settingsForm(array $form, array &$form_state) {
-    $element['size'] = array(
-      '#type' => 'number',
-      '#title' => t('Size of textfield'),
-      '#default_value' => $this->getSetting('size'),
-      '#required' => TRUE,
-      '#min' => 1,
-    );
-    $element['placeholder'] = array(
-      '#type' => 'textfield',
-      '#title' => t('Placeholder'),
-      '#default_value' => $this->getSetting('placeholder'),
-      '#description' => t('Text that will be shown inside the field until a value is entered. This hint is usually a sample value or a brief description of the expected format.'),
-    );
-    return $element;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function settingsSummary() {
-    $summary = array();
-
-    $summary[] = t('URL field size: !size', array('!size' => $this->getSetting('size')));
-    $placeholder = $this->getSetting('placeholder');
-    if (!empty($placeholder)) {
-      $summary[] = t('Placeholder: @placeholder', array('@placeholder' => $placeholder));
-    }
-
-    return $summary;
-  }
-
-  /**
-   * {@inheritdoc}
-   */
-  public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, array &$form_state) {
-    $element['value'] = $element + array(
-      '#type' => 'url',
-      '#default_value' => isset($items[$delta]->value) ? $items[$delta]->value : NULL,
-      '#size' => $this->getSetting('size'),
-      '#placeholder' => $this->getSetting('placeholder'),
-      '#maxlength' => $this->getFieldSetting('max_length'),
-    );
-
-    return $element;
-  }
-
-}
diff -u b/core/modules/aggregator/lib/Drupal/aggregator/Entity/Feed.php b/core/modules/aggregator/lib/Drupal/aggregator/Entity/Feed.php
--- b/core/modules/aggregator/lib/Drupal/aggregator/Entity/Feed.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Entity/Feed.php
@@ -149,8 +149,7 @@
       ->setDisplayOptions('form', array(
         'type' => 'string',
         'weight' => -5,
-      ))
-      ->setDisplayConfigurable('form', TRUE);
+      ));
 
     $fields['langcode'] = FieldDefinition::create('language')
       ->setLabel(t('Language code'))
@@ -160,12 +159,11 @@
       ->setLabel(t('URL'))
       ->setDescription(t('The URL to the feed.'))
       ->setRequired(TRUE)
-      ->setSetting('max_length', 100)
+      ->setSetting('max_length', NULL)
       ->setDisplayOptions('form', array(
         'type' => 'uri',
         'weight' => -4,
-      ))
-      ->setDisplayConfigurable('form', TRUE);
+      ));
 
     $fields['refresh'] = FieldDefinition::create('integer')
       ->setLabel(t('Refresh'))
diff -u b/core/modules/aggregator/lib/Drupal/aggregator/Tests/AggregatorTestBase.php b/core/modules/aggregator/lib/Drupal/aggregator/Tests/AggregatorTestBase.php
--- b/core/modules/aggregator/lib/Drupal/aggregator/Tests/AggregatorTestBase.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Tests/AggregatorTestBase.php
@@ -56,7 +56,7 @@
     $this->drupalPostForm('aggregator/sources/add', $edit, t('Save'));
     $this->assertRaw(t('The feed %name has been added.', array('%name' => $edit['title[0][value]'])), format_string('The feed !name has been added.', array('!name' => $edit['title[0][value]'])));
 
-    $fid = db_query("SELECT fid FROM {aggregator_feed} WHERE title = :title AND url = :url", array(':title' => $edit['title[0][value]'], ':url' => $edit['url']))->fetchField();
+    $fid = db_query("SELECT fid FROM {aggregator_feed} WHERE title = :title AND url = :url", array(':title' => $edit['title[0][value]'], ':url' => $edit['url[0][value]']))->fetchField();
     $this->assertTrue(!empty($fid), 'The feed found in database.');
     return aggregator_feed_load($fid);
   }
@@ -94,7 +94,7 @@
     }
     $edit += array(
       'title[0][value]' => $feed_name,
-      'url' => $feed_url,
+      'url[0][value]' => $feed_url,
       'refresh' => '900',
     );
     return $edit;
@@ -233,7 +233,7 @@
   function getValidOpml($feeds) {
     // Properly escape URLs so that XML parsers don't choke on them.
     foreach ($feeds as &$feed) {
-      $feed['url'] = htmlspecialchars($feed['url']);
+      $feed['url[0][value]'] = htmlspecialchars($feed['url[0][value]']);
     }
     /**
      * Does not have an XML declaration, must pass the parser.
@@ -243,18 +243,18 @@
   <head></head>
   <body>
     <!-- First feed to be imported. -->
-    <outline text="{$feeds[0]['title[0][value]']}" xmlurl="{$feeds[0]['url']}" />
+    <outline text="{$feeds[0]['title[0][value]']}" xmlurl="{$feeds[0]['url[0][value]']}" />
 
     <!-- Second feed. Test string delimitation and attribute order. -->
-    <outline xmlurl='{$feeds[1]['url']}' text='{$feeds[1]['title[0][value]']}'/>
+    <outline xmlurl='{$feeds[1]['url[0][value]']}' text='{$feeds[1]['title[0][value]']}'/>
 
     <!-- Test for duplicate URL and title. -->
-    <outline xmlurl="{$feeds[0]['url']}" text="Duplicate URL"/>
+    <outline xmlurl="{$feeds[0]['url[0][value]']}" text="Duplicate URL"/>
     <outline xmlurl="http://duplicate.title" text="{$feeds[1]['title[0][value]']}"/>
 
     <!-- Test that feeds are only added with required attributes. -->
     <outline text="{$feeds[2]['title[0][value]']}" />
-    <outline xmlurl="{$feeds[2]['url']}" />
+    <outline xmlurl="{$feeds[2]['url[0][value]']}" />
   </body>
 </opml>
 EOF;
diff -u b/core/modules/aggregator/lib/Drupal/aggregator/Tests/ImportOpmlTest.php b/core/modules/aggregator/lib/Drupal/aggregator/Tests/ImportOpmlTest.php
--- b/core/modules/aggregator/lib/Drupal/aggregator/Tests/ImportOpmlTest.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Tests/ImportOpmlTest.php
@@ -101,7 +101,7 @@
       'refresh'       => '900',
     );
     $this->drupalPostForm('admin/config/services/aggregator/add/opml', $edit, t('Import'));
-    $this->assertRaw(t('A feed with the URL %url already exists.', array('%url' => $feeds[0]['url'])), 'Verifying that a duplicate URL was identified');
+    $this->assertRaw(t('A feed with the URL %url already exists.', array('%url' => $feeds[0]['url[0][value]'])), 'Verifying that a duplicate URL was identified');
     $this->assertRaw(t('A feed named %title already exists.', array('%title' => $feeds[1]['title[0][value]'])), 'Verifying that a duplicate title was identified');
 
     $after = db_query('SELECT COUNT(*) FROM {aggregator_feed}')->fetchField();
@@ -115,8 +115,8 @@
       $refresh = $refresh && $feed->refresh == 900;
     }
 
-    $this->assertEqual($title[$feeds[0]['url']], $feeds[0]['title[0][value]'], 'First feed was added correctly.');
-    $this->assertEqual($url[$feeds[1]['title[0][value]']], $feeds[1]['url'], 'Second feed was added correctly.');
+    $this->assertEqual($title[$feeds[0]['url[0][value]']], $feeds[0]['title[0][value]'], 'First feed was added correctly.');
+    $this->assertEqual($url[$feeds[1]['title[0][value]']], $feeds[1]['url[0][value]'], 'Second feed was added correctly.');
     $this->assertTrue($refresh, 'Refresh times are correct.');
   }
 
diff -u b/core/modules/aggregator/lib/Drupal/aggregator/Tests/UpdateFeedItemTest.php b/core/modules/aggregator/lib/Drupal/aggregator/Tests/UpdateFeedItemTest.php
--- b/core/modules/aggregator/lib/Drupal/aggregator/Tests/UpdateFeedItemTest.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Tests/UpdateFeedItemTest.php
@@ -38,16 +38,16 @@
     // Test updating feed items without valid timestamp information.
     $edit = array(
       'title[0][value]' => "Feed without publish timestamp",
-      'url' => $this->getRSS091Sample(),
+      'url[0][value]' => $this->getRSS091Sample(),
     );
 
-    $this->drupalGet($edit['url']);
-    $this->assertResponse(array(200), format_string('URL !url is accessible', array('!url' => $edit['url'])));
+    $this->drupalGet($edit['url[0][value]']);
+    $this->assertResponse(array(200), format_string('URL !url is accessible', array('!url' => $edit['url[0][value]'])));
 
     $this->drupalPostForm('aggregator/sources/add', $edit, t('Save'));
     $this->assertRaw(t('The feed %name has been added.', array('%name' => $edit['title[0][value]'])), format_string('The feed !name has been added.', array('!name' => $edit['title[0][value]'])));
 
-    $fid = db_query("SELECT fid FROM {aggregator_feed} WHERE url = :url", array(':url' => $edit['url']))->fetchField();
+    $fid = db_query("SELECT fid FROM {aggregator_feed} WHERE url = :url", array(':url' => $edit['url[0][value]']))->fetchField();
     $feed = aggregator_feed_load($fid);
 
     $feed->refreshItems();
diff -u b/core/modules/aggregator/lib/Drupal/aggregator/Tests/UpdateFeedTest.php b/core/modules/aggregator/lib/Drupal/aggregator/Tests/UpdateFeedTest.php
--- b/core/modules/aggregator/lib/Drupal/aggregator/Tests/UpdateFeedTest.php
+++ b/core/modules/aggregator/lib/Drupal/aggregator/Tests/UpdateFeedTest.php
@@ -23,7 +23,7 @@
    * Creates a feed and attempts to update it.
    */
   function testUpdateFeed() {
-    $remamining_fields = array('title[0][value]', 'url', '');
+    $remamining_fields = array('title[0][value]', 'url[0][value]', '');
     foreach ($remamining_fields as $same_field) {
       $feed = $this->createFeed();
 
@@ -38,7 +38,7 @@
 
       // Check feed data.
       $this->assertEqual($this->getUrl(), url('aggregator/sources/' . $feed->id(), array('absolute' => TRUE)));
-      $this->assertTrue($this->uniqueFeed($edit['title[0][value]'], $edit['url']), 'The feed is unique.');
+      $this->assertTrue($this->uniqueFeed($edit['title[0][value]'], $edit['url[0][value]']), 'The feed is unique.');
 
       // Check feed source.
       $this->drupalGet('aggregator/sources/' . $feed->id());
only in patch2:
unchanged:
--- /dev/null
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldWidget/UriWidget.php
@@ -0,0 +1,86 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\Core\Field\Plugin\Field\FieldWidget\UriWidget.
+ */
+
+namespace Drupal\Core\Field\Plugin\Field\FieldWidget;
+
+use Drupal\Core\Field\FieldItemListInterface;
+use Drupal\Core\Field\WidgetBase;
+
+/**
+ * Plugin implementation of the 'uri' widget.
+ *
+ * @FieldWidget(
+ *   id = "uri",
+ *   label = @Translation("Uri field"),
+ *   field_types = {
+ *     "uri"
+ *   }
+ * )
+ */
+class UriWidget extends WidgetBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function defaultSettings() {
+    return array(
+      'size' => 60,
+      'placeholder' => '',
+    ) + parent::defaultSettings();
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsForm(array $form, array &$form_state) {
+    $element['size'] = array(
+      '#type' => 'number',
+      '#title' => t('Size of textfield'),
+      '#default_value' => $this->getSetting('size'),
+      '#required' => TRUE,
+      '#min' => 1,
+    );
+    $element['placeholder'] = array(
+      '#type' => 'textfield',
+      '#title' => t('Placeholder'),
+      '#default_value' => $this->getSetting('placeholder'),
+      '#description' => t('Text that will be shown inside the field until a value is entered. This hint is usually a sample value or a brief description of the expected format.'),
+    );
+    return $element;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function settingsSummary() {
+    $summary = array();
+
+    $summary[] = t('URL field size: !size', array('!size' => $this->getSetting('size')));
+    $placeholder = $this->getSetting('placeholder');
+    if (!empty($placeholder)) {
+      $summary[] = t('Placeholder: @placeholder', array('@placeholder' => $placeholder));
+    }
+
+    return $summary;
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function formElement(FieldItemListInterface $items, $delta, array $element, array &$form, array &$form_state) {
+    $element['value'] = $element + array(
+      '#type' => 'url',
+      '#default_value' => isset($items[$delta]->value) ? $items[$delta]->value : NULL,
+      '#size' => $this->getSetting('size'),
+      '#placeholder' => $this->getSetting('placeholder'),
+      '#maxlength' => $this->getFieldSetting('max_length'),
+    );
+
+    return $element;
+  }
+
+}