diff -u b/core/includes/common.inc b/core/includes/common.inc
--- b/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -128,13 +128,6 @@
 const JS_THEME = 100;
 
 /**
- * Error code indicating that the request exceeded the specified timeout.
- *
- * @see drupal_http_request()
- */
-const HTTP_REQUEST_TIMEOUT = -1;
-
-/**
  * @defgroup block_caching Block Caching
  * @{
  * Constants that define each block's caching state.
only in patch2:
unchanged:
--- a/core/modules/statistics/lib/Drupal/statistics/Tests/Views/IntegrationTest.php
+++ b/core/modules/statistics/lib/Drupal/statistics/Tests/Views/IntegrationTest.php
@@ -81,11 +81,11 @@ public function testNodeCounterIntegration() {
     // Manually calling statistics.php, simulating ajax behavior.
     // @see \Drupal\statistics\Tests\StatisticsLoggingTest::testLogging().
     $post = http_build_query(array('nid' => $this->node->id()));
-    $headers = array('Content-Type' => 'application/x-www-form-urlencoded');
     global $base_url;
     $stats_path = $base_url . '/' . drupal_get_path('module', 'statistics'). '/statistics.php';
-    drupal_http_request($stats_path, array('method' => 'POST', 'data' => $post, 'headers' => $headers, 'timeout' => 10000));
-
+    $client = \Drupal::httpClient();
+    $client->setConfig(array('curl.options' => array(CURLOPT_TIMEOUT => 10)));
+    $client->post($stats_path, array(), $post)->send();
     $this->drupalGet('test_statistics_integration');
 
     $expected = statistics_get($this->node->id());