Merge branch '4.4' into 5.0

* 4.4:
  Add documentation about data collectors late collect

Author: javiereguiluz

profiler/data_collector.rst

@@ -79,6 +79,12 @@ request::
     :doc:`/testing/profiling`) so it's recommended to return a string which is
     short, lowercase and without white spaces.
 
+The ``collect()`` method is called during the :ref:`kernel.response <component-http-kernel-kernel-response>`
+event. If you need to collect data that is only available later, implement
+:class:`Symfony\\Component\\HttpKernel\\DataCollector\\LateDataCollectorInterface`
+and define the ``lateCollect()`` method, which is invoked just before the profiler
+data serialization (during :ref:`kernel.terminate <component-http-kernel-kernel-terminate>` event).
+
 .. _data_collector_tag:
 
 Enabling Custom Data Collectors