diff --git a/src/Symfony/Component/HttpFoundation/CHANGELOG.md b/src/Symfony/Component/HttpFoundation/CHANGELOG.md
index e1fdf77b9b8ae..aa2500f57a40c 100644
--- a/src/Symfony/Component/HttpFoundation/CHANGELOG.md
+++ b/src/Symfony/Component/HttpFoundation/CHANGELOG.md
@@ -1,6 +1,23 @@
 CHANGELOG
 =========
 
+4.0.0
+-----
+
+ * the `Request::setTrustedHeaderName()` and `Request::getTrustedHeaderName()`
+   methods have been removed
+ * the `Request::HEADER_CLIENT_IP` constant has been removed, use
+   `Request::HEADER_X_FORWARDED_FOR` instead
+ * the `Request::HEADER_CLIENT_HOST` constant has been removed, use
+   `Request::HEADER_X_FORWARDED_HOST` instead
+ * the `Request::HEADER_CLIENT_PROTO` constant has been removed, use
+   `Request::HEADER_X_FORWARDED_PROTO` instead
+ * the `Request::HEADER_CLIENT_PORT` constant has been removed, use
+   `Request::HEADER_X_FORWARDED_PORT` instead
+ * checking for cacheable HTTP methods using the `Request::isMethodSafe()`
+   method (by not passing `false` as its argument) is not supported anymore and
+   throws a `\BadMethodCallException`
+
 3.3.0
 -----
 
diff --git a/src/Symfony/Component/HttpFoundation/Request.php b/src/Symfony/Component/HttpFoundation/Request.php
index c15d7d3165559..35ac77d01e727 100644
--- a/src/Symfony/Component/HttpFoundation/Request.php
+++ b/src/Symfony/Component/HttpFoundation/Request.php
@@ -38,15 +38,6 @@ class Request
     const HEADER_X_FORWARDED_ALL = 0b11110; // All "X-Forwarded-*" headers
     const HEADER_X_FORWARDED_AWS_ELB = 0b11010; // AWS ELB doesn't send X-Forwarded-Host
 
-    /** @deprecated since version 3.3, to be removed in 4.0 */
-    const HEADER_CLIENT_IP = self::HEADER_X_FORWARDED_FOR;
-    /** @deprecated since version 3.3, to be removed in 4.0 */
-    const HEADER_CLIENT_HOST = self::HEADER_X_FORWARDED_HOST;
-    /** @deprecated since version 3.3, to be removed in 4.0 */
-    const HEADER_CLIENT_PROTO = self::HEADER_X_FORWARDED_PROTO;
-    /** @deprecated since version 3.3, to be removed in 4.0 */
-    const HEADER_CLIENT_PORT = self::HEADER_X_FORWARDED_PORT;
-
     const METHOD_HEAD = 'HEAD';
     const METHOD_GET = 'GET';
     const METHOD_POST = 'POST';
@@ -73,25 +64,6 @@ class Request
      */
     protected static $trustedHosts = array();
 
-    /**
-     * Names for headers that can be trusted when
-     * using trusted proxies.
-     *
-     * The FORWARDED header is the standard as of rfc7239.
-     *
-     * The other headers are non-standard, but widely used
-     * by popular reverse proxies (like Apache mod_proxy or Amazon EC2).
-     *
-     * @deprecated since version 3.3, to be removed in 4.0
-     */
-    protected static $trustedHeaders = array(
-        self::HEADER_FORWARDED => 'FORWARDED',
-        self::HEADER_CLIENT_IP => 'X_FORWARDED_FOR',
-        self::HEADER_CLIENT_HOST => 'X_FORWARDED_HOST',
-        self::HEADER_CLIENT_PROTO => 'X_FORWARDED_PROTO',
-        self::HEADER_CLIENT_PORT => 'X_FORWARDED_PORT',
-    );
-
     protected static $httpMethodParameterOverride = false;
 
     /**
@@ -226,15 +198,6 @@ class Request
 
     private static $trustedHeaderSet = -1;
 
-    /** @deprecated since version 3.3, to be removed in 4.0 */
-    private static $trustedHeaderNames = array(
-        self::HEADER_FORWARDED => 'FORWARDED',
-        self::HEADER_CLIENT_IP => 'X_FORWARDED_FOR',
-        self::HEADER_CLIENT_HOST => 'X_FORWARDED_HOST',
-        self::HEADER_CLIENT_PROTO => 'X_FORWARDED_PROTO',
-        self::HEADER_CLIENT_PORT => 'X_FORWARDED_PORT',
-    );
-
     private static $forwardedParams = array(
         self::HEADER_X_FORWARDED_FOR => 'for',
         self::HEADER_X_FORWARDED_HOST => 'host',
@@ -242,6 +205,23 @@ class Request
         self::HEADER_X_FORWARDED_PORT => 'host',
     );
 
+    /**
+     * Names for headers that can be trusted when
+     * using trusted proxies.
+     *
+     * The FORWARDED header is the standard as of rfc7239.
+     *
+     * The other headers are non-standard, but widely used
+     * by popular reverse proxies (like Apache mod_proxy or Amazon EC2).
+     */
+    private static $trustedHeaders = array(
+        self::HEADER_FORWARDED => 'FORWARDED',
+        self::HEADER_X_FORWARDED_FOR => 'X_FORWARDED_FOR',
+        self::HEADER_X_FORWARDED_HOST => 'X_FORWARDED_HOST',
+        self::HEADER_X_FORWARDED_PROTO => 'X_FORWARDED_PROTO',
+        self::HEADER_X_FORWARDED_PORT => 'X_FORWARDED_PORT',
+    );
+
     /**
      * Constructor.
      *
@@ -572,20 +552,9 @@ public function overrideGlobals()
      *
      * @throws \InvalidArgumentException When $trustedHeaderSet is invalid
      */
-    public static function setTrustedProxies(array $proxies/*, int $trustedHeaderSet*/)
+    public static function setTrustedProxies(array $proxies, int $trustedHeaderSet)
     {
         self::$trustedProxies = $proxies;
-
-        if (2 > func_num_args()) {
-            @trigger_error(sprintf('The %s() method expects a bit field of Request::HEADER_* as second argument since version 3.3. Defining it will be required in 4.0. ', __METHOD__), E_USER_DEPRECATED);
-
-            return;
-        }
-        $trustedHeaderSet = (int) func_get_arg(1);
-
-        foreach (self::$trustedHeaderNames as $header => $name) {
-            self::$trustedHeaders[$header] = $header & $trustedHeaderSet ? $name : null;
-        }
         self::$trustedHeaderSet = $trustedHeaderSet;
     }
 
@@ -635,68 +604,6 @@ public static function getTrustedHosts()
         return self::$trustedHostPatterns;
     }
 
-    /**
-     * Sets the name for trusted headers.
-     *
-     * The following header keys are supported:
-     *
-     *  * Request::HEADER_CLIENT_IP:    defaults to X-Forwarded-For   (see getClientIp())
-     *  * Request::HEADER_CLIENT_HOST:  defaults to X-Forwarded-Host  (see getHost())
-     *  * Request::HEADER_CLIENT_PORT:  defaults to X-Forwarded-Port  (see getPort())
-     *  * Request::HEADER_CLIENT_PROTO: defaults to X-Forwarded-Proto (see getScheme() and isSecure())
-     *  * Request::HEADER_FORWARDED:    defaults to Forwarded         (see RFC 7239)
-     *
-     * Setting an empty value allows to disable the trusted header for the given key.
-     *
-     * @param string $key   The header key
-     * @param string $value The header name
-     *
-     * @throws \InvalidArgumentException
-     *
-     * @deprecated since version 3.3, to be removed in 4.0. Use the $trustedHeaderSet argument of the Request::setTrustedProxies() method instead.
-     */
-    public static function setTrustedHeaderName($key, $value)
-    {
-        @trigger_error(sprintf('The "%s()" method is deprecated since version 3.3 and will be removed in 4.0. Use the $trustedHeaderSet argument of the Request::setTrustedProxies() method instead.', __METHOD__), E_USER_DEPRECATED);
-
-        if (!array_key_exists($key, self::$trustedHeaders)) {
-            throw new \InvalidArgumentException(sprintf('Unable to set the trusted header name for key "%s".', $key));
-        }
-
-        self::$trustedHeaders[$key] = $value;
-
-        if (null !== $value) {
-            self::$trustedHeaderNames[$key] = $value;
-            self::$trustedHeaderSet |= $key;
-        } else {
-            self::$trustedHeaderSet &= ~$key;
-        }
-    }
-
-    /**
-     * Gets the trusted proxy header name.
-     *
-     * @param string $key The header key
-     *
-     * @return string The header name
-     *
-     * @throws \InvalidArgumentException
-     *
-     * @deprecated since version 3.3, to be removed in 4.0. Use the Request::getTrustedHeaderSet() method instead.
-     */
-    public static function getTrustedHeaderName($key)
-    {
-        if (2 > func_num_args() || func_get_arg(1)) {
-            @trigger_error(sprintf('The "%s()" method is deprecated since version 3.3 and will be removed in 4.0. Use the Request::getTrustedHeaderSet() method instead.', __METHOD__), E_USER_DEPRECATED);
-        }
-
-        if (!array_key_exists($key, self::$trustedHeaders)) {
-            throw new \InvalidArgumentException(sprintf('Unable to get the trusted header name for key "%s".', $key));
-        }
-
-        return self::$trustedHeaders[$key];
-    }
-
     /**
      * Normalizes a query string.
      *
@@ -864,7 +771,7 @@ public function getClientIps()
             return array($ip);
         }
 
-        return $this->getTrustedValues(self::HEADER_CLIENT_IP, $ip) ?: array($ip);
+        return $this->getTrustedValues(self::HEADER_X_FORWARDED_FOR, $ip) ?: array($ip);
     }
 
     /**
@@ -991,9 +898,9 @@ public function getScheme()
      */
     public function getPort()
     {
-        if ($this->isFromTrustedProxy() && $host = $this->getTrustedValues(self::HEADER_CLIENT_PORT)) {
+        if ($this->isFromTrustedProxy() && $host = $this->getTrustedValues(self::HEADER_X_FORWARDED_PORT)) {
             $host = $host[0];
-        } elseif ($this->isFromTrustedProxy() && $host = $this->getTrustedValues(self::HEADER_CLIENT_HOST)) {
+        } elseif ($this->isFromTrustedProxy() && $host = $this->getTrustedValues(self::HEADER_X_FORWARDED_HOST)) {
             $host = $host[0];
         } elseif (!$host = $this->headers->get('HOST')) {
             return $this->server->get('SERVER_PORT');
@@ -1209,7 +1116,7 @@ public function getQueryString()
      */
     public function isSecure()
     {
-        if ($this->isFromTrustedProxy() && $proto = $this->getTrustedValues(self::HEADER_CLIENT_PROTO)) {
+        if ($this->isFromTrustedProxy() && $proto = $this->getTrustedValues(self::HEADER_X_FORWARDED_PROTO)) {
             return in_array(strtolower($proto[0]), array('https', 'on', 'ssl', '1'), true);
         }
 
@@ -1236,7 +1143,7 @@ public function isSecure()
      */
     public function getHost()
     {
-        if ($this->isFromTrustedProxy() && $host = $this->getTrustedValues(self::HEADER_CLIENT_HOST)) {
+        if ($this->isFromTrustedProxy() && $host = $this->getTrustedValues(self::HEADER_X_FORWARDED_HOST)) {
             $host = $host[0];
         } elseif (!$host = $this->headers->get('HOST')) {
             if (!$host = $this->server->get('SERVER_NAME')) {
@@ -1526,11 +1433,8 @@ public function isMethod($method)
     public function isMethodSafe(/* $andCacheable = true */)
     {
         if (!func_num_args() || func_get_arg(0)) {
-            // This deprecation should be turned into a BadMethodCallException in 4.0 (without adding the argument in the signature)
-            // then setting $andCacheable to false should be deprecated in 4.1
-            @trigger_error('Checking only for cacheable HTTP methods with Symfony\Component\HttpFoundation\Request::isMethodSafe() is deprecated since version 3.2 and will throw an exception in 4.0. Disable checking only for cacheable methods by calling the method with `false` as first argument or use the Request::isMethodCacheable() instead.', E_USER_DEPRECATED);
-
-            return in_array($this->getMethod(), array('GET', 'HEAD'));
+            // setting $andCacheable to false should be deprecated in 4.1
+            throw new \BadMethodCallException('Checking only for cacheable HTTP methods with Symfony\Component\HttpFoundation\Request::isMethodSafe() is not supported.', E_USER_DEPRECATED);
         }
 
         return in_array($this->getMethod(), array('GET', 'HEAD', 'OPTIONS', 'TRACE'));
@@ -2022,7 +1926,7 @@ private function getTrustedValues($type, $ip = null)
 
         if (self::$trustedHeaders[$type] && $this->headers->has(self::$trustedHeaders[$type])) {
             foreach (explode(',', $this->headers->get(self::$trustedHeaders[$type])) as $v) {
-                $clientValues[] = (self::HEADER_CLIENT_PORT === $type ? '0.0.0.0:' : '').trim($v);
+                $clientValues[] = (self::HEADER_X_FORWARDED_PORT === $type ? '0.0.0.0:' : '').trim($v);
             }
         }
 
diff --git a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
index 789fa7c8970ae..703857b00b81b 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
@@ -1711,53 +1711,6 @@ public function testTrustedProxiesXForwardedFor()
         $this->assertTrue($request->isSecure());
     }
 
-    /**
-     * @group legacy
-     * @expectedDeprecation The "Symfony\Component\HttpFoundation\Request::setTrustedHeaderName()" method is deprecated since version 3.3 and will be removed in 4.0. Use the $trustedHeaderSet argument of the Request::setTrustedProxies() method instead.
-     */
-    public function testLegacyTrustedProxies()
-    {
-        $request = Request::create('http://example.com/');
-        $request->server->set('REMOTE_ADDR', '3.3.3.3');
-        $request->headers->set('X_FORWARDED_FOR', '1.1.1.1, 2.2.2.2');
-        $request->headers->set('X_FORWARDED_HOST', 'foo.example.com, real.example.com:8080');
-        $request->headers->set('X_FORWARDED_PROTO', 'https');
-        $request->headers->set('X_FORWARDED_PORT', 443);
-        $request->headers->set('X_MY_FOR', '3.3.3.3, 4.4.4.4');
-        $request->headers->set('X_MY_HOST', 'my.example.com');
-        $request->headers->set('X_MY_PROTO', 'http');
-        $request->headers->set('X_MY_PORT', 81);
-
-        Request::setTrustedProxies(array('3.3.3.3', '2.2.2.2'), Request::HEADER_X_FORWARDED_ALL);
-
-        // custom header names
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_IP, 'X_MY_FOR');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_HOST, 'X_MY_HOST');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PORT, 'X_MY_PORT');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PROTO, 'X_MY_PROTO');
-        $this->assertEquals('4.4.4.4', $request->getClientIp());
-        $this->assertEquals('my.example.com', $request->getHost());
-        $this->assertEquals(81, $request->getPort());
-        $this->assertFalse($request->isSecure());
-
-        // disabling via empty header names
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_IP, null);
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_HOST, null);
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PORT, null);
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PROTO, null);
-        $this->assertEquals('3.3.3.3', $request->getClientIp());
-        $this->assertEquals('example.com', $request->getHost());
-        $this->assertEquals(80, $request->getPort());
-        $this->assertFalse($request->isSecure());
-
-        //reset
-        Request::setTrustedHeaderName(Request::HEADER_FORWARDED, 'FORWARDED');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_IP, 'X_FORWARDED_FOR');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_HOST, 'X_FORWARDED_HOST');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PORT, 'X_FORWARDED_PORT');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PROTO, 'X_FORWARDED_PROTO');
-    }
-
     public function testTrustedProxiesForwarded()
     {
         $request = Request::create('http://example.com/');
@@ -1807,26 +1760,6 @@ public function testTrustedProxiesForwarded()
         $this->assertTrue($request->isSecure());
     }
 
-    /**
-     * @group legacy
-     * @expectedException \InvalidArgumentException
-     */
-    public function testSetTrustedProxiesInvalidHeaderName()
-    {
-        Request::create('http://example.com/');
-        Request::setTrustedHeaderName('bogus name', 'X_MY_FOR');
-    }
-
-    /**
-     * @group legacy
-     * @expectedException \InvalidArgumentException
-     */
-    public function testGetTrustedProxiesInvalidHeaderName()
-    {
-        Request::create('http://example.com/');
-        Request::getTrustedHeaderName('bogus name');
-    }
-
     /**
      * @dataProvider iisRequestUriProvider
      */
@@ -2082,14 +2015,13 @@ public function methodSafeProvider()
     }
 
     /**
-     * @group legacy
-     * @expectedDeprecation Checking only for cacheable HTTP methods with Symfony\Component\HttpFoundation\Request::isMethodSafe() is deprecated since version 3.2 and will throw an exception in 4.0. Disable checking only for cacheable methods by calling the method with `false` as first argument or use the Request::isMethodCacheable() instead.
+     * @expectedException \BadMethodCallException
      */
     public function testMethodSafeChecksCacheable()
     {
         $request = new Request();
         $request->setMethod('OPTIONS');
-        $this->assertFalse($request->isMethodSafe());
+        $request->isMethodSafe();
     }
 
     /**
@@ -2117,61 +2049,6 @@ public function methodCacheableProvider()
             array('CONNECT', false),
         );
     }
-
-    /**
-     * @group legacy
-     */
-    public function testGetTrustedHeaderName()
-    {
-        Request::setTrustedProxies(array('8.8.8.8'), Request::HEADER_X_FORWARDED_ALL);
-
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_FORWARDED));
-        $this->assertSame('X_FORWARDED_FOR', Request::getTrustedHeaderName(Request::HEADER_CLIENT_IP));
-        $this->assertSame('X_FORWARDED_HOST', Request::getTrustedHeaderName(Request::HEADER_CLIENT_HOST));
-        $this->assertSame('X_FORWARDED_PORT', Request::getTrustedHeaderName(Request::HEADER_CLIENT_PORT));
-        $this->assertSame('X_FORWARDED_PROTO', Request::getTrustedHeaderName(Request::HEADER_CLIENT_PROTO));
-
-        Request::setTrustedProxies(array('8.8.8.8'), Request::HEADER_FORWARDED);
-
-        $this->assertSame('FORWARDED', Request::getTrustedHeaderName(Request::HEADER_FORWARDED));
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_CLIENT_IP));
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_CLIENT_HOST));
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_CLIENT_PORT));
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_CLIENT_PROTO));
-
-        Request::setTrustedHeaderName(Request::HEADER_FORWARDED, 'A');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_IP, 'B');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_HOST, 'C');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PORT, 'D');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PROTO, 'E');
-
-        Request::setTrustedProxies(array('8.8.8.8'), Request::HEADER_FORWARDED);
-
-        $this->assertSame('A', Request::getTrustedHeaderName(Request::HEADER_FORWARDED));
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_CLIENT_IP));
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_CLIENT_HOST));
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_CLIENT_PORT));
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_CLIENT_PROTO));
-
-        Request::setTrustedProxies(array('8.8.8.8'), Request::HEADER_X_FORWARDED_ALL);
-
-        $this->assertNull(Request::getTrustedHeaderName(Request::HEADER_FORWARDED));
-        $this->assertSame('B', Request::getTrustedHeaderName(Request::HEADER_CLIENT_IP));
-        $this->assertSame('C', Request::getTrustedHeaderName(Request::HEADER_CLIENT_HOST));
-        $this->assertSame('D', Request::getTrustedHeaderName(Request::HEADER_CLIENT_PORT));
-        $this->assertSame('E', Request::getTrustedHeaderName(Request::HEADER_CLIENT_PROTO));
-
-        Request::setTrustedProxies(array('8.8.8.8'), Request::HEADER_FORWARDED);
-
-        $this->assertSame('A', Request::getTrustedHeaderName(Request::HEADER_FORWARDED));
-
-        //reset
-        Request::setTrustedHeaderName(Request::HEADER_FORWARDED, 'FORWARDED');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_IP, 'X_FORWARDED_FOR');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_HOST, 'X_FORWARDED_HOST');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PORT, 'X_FORWARDED_PORT');
-        Request::setTrustedHeaderName(Request::HEADER_CLIENT_PROTO, 'X_FORWARDED_PROTO');
-    }
 }
 
 class RequestContentProxy extends Request
diff --git a/src/Symfony/Component/HttpKernel/Fragment/InlineFragmentRenderer.php b/src/Symfony/Component/HttpKernel/Fragment/InlineFragmentRenderer.php
index 437b40bf95953..2365f922ee696 100644
--- a/src/Symfony/Component/HttpKernel/Fragment/InlineFragmentRenderer.php
+++ b/src/Symfony/Component/HttpKernel/Fragment/InlineFragmentRenderer.php
@@ -115,21 +115,10 @@ protected function createSubRequest($uri, Request $request)
         $cookies = $request->cookies->all();
         $server = $request->server->all();
 
-        // Override the arguments to emulate a sub-request.
-        // Sub-request object will point to localhost as client ip and real client ip
-        // will be included into trusted header for client ip
-        try {
-            if (Request::HEADER_X_FORWARDED_FOR & Request::getTrustedHeaderSet()) {
-                $currentXForwardedFor = $request->headers->get('X_FORWARDED_FOR', '');
-
-                $server['HTTP_X_FORWARDED_FOR'] = ($currentXForwardedFor ? $currentXForwardedFor.', ' : '').$request->getClientIp();
-            } elseif (method_exists(Request::class, 'getTrustedHeaderName') && $trustedHeaderName = Request::getTrustedHeaderName(Request::HEADER_CLIENT_IP, false)) {
-                $currentXForwardedFor = $request->headers->get($trustedHeaderName, '');
+        if (Request::HEADER_X_FORWARDED_FOR & Request::getTrustedHeaderSet()) {
+            $currentXForwardedFor = $request->headers->get('X_FORWARDED_FOR', '');
 
-                $server['HTTP_'.$trustedHeaderName] = ($currentXForwardedFor ? $currentXForwardedFor.', ' : '').$request->getClientIp();
-            }
-        } catch (\InvalidArgumentException $e) {
-            // Do nothing
+            $server['HTTP_X_FORWARDED_FOR'] = ($currentXForwardedFor ? $currentXForwardedFor.', ' : '').$request->getClientIp();
         }
 
         $server['REMOTE_ADDR'] = '127.0.0.1';