[BrowserKit] Document the integration with HttpClient

Author: javiereguiluz

components/browser_kit.rst

@@ -10,9 +10,10 @@ The BrowserKit Component
 
 .. note::
 
-    The BrowserKit component can only make internal requests to your application.
-    If you need to make requests to external sites and applications, consider
-    using `Goutte`_, a simple web scraper based on Symfony Components.
+    In Symfony versions prior to 4.3, the BrowserKit component could only make
+    internal requests to your application. Starting from Symfony 4.3, this
+    component can also :ref:`make HTTP requests to any public site <component-browserkit-external-requests>`
+    when using it in combination with the :doc:`HttpClient component </components/http_client>`_.
 
 Installation
 ------------
@@ -279,6 +280,38 @@ also delete all the cookies::
     // reset the client (history and cookies are cleared too)
     $client->restart();
 
+.. _ component-browserkit-external-requests:
+
+Making External HTTP Requests
+-----------------------------
+
+So far, all the examples in this article have assumed that you are making
+internal requests to your own application. However, you can run the exact same
+examples when making HTTP requests to external web sites and applications.
+
+First, install and configure the :doc:`HttpClient component </components/http_client>`_.
+Then, use the :class:`Symfony\\Component\\HttpClient\\BrowserClient` to create
+the client that will make the external HTTP requests::
+
+    use Symfony\Component\HttpClient\BrowserClient;
+    use Symfony\Component\HttpClient\HttpClient;
+
+    $browser = new BrowserClient(HttpClient::create());
+
+You can now use any of the methods shown in this article to extract information,
+click links, submit forms, etc. This means that you no longer need to use a
+dedicated web crawler or scraper such as `Goutte`_::
+
+    // ...
+    $browser = new BrowserClient(HttpClient::create());
+
+    $browser->request('GET', 'https://github.com');
+    $browser->clickLink('Sign in');
+    $browser->submitForm('Sign in', ['login' => '...', 'password' => '...']);
+    $openPullRequests = trim($browser->clickLink('Pull requests')->filter(
+        '.table-list-header-toggle a:nth-child(1)'
+    )->text());
+
 Learn more
 ----------