Precision about dependency injection resolving

[JasonBenett]

The resolving of dependency injection in a Controller action is available if the controller is defined as a service. I think this comportment have to be more explicit in this documentation's part to prevent some user's incomprehension.

[weaverryan]

I think adding a note like this is a good idea... but we should probably add it in a bunch of different places where we suddenly autowire a controller argument like this (we could remove those notes in a few versions).

For the note, how about:

.. note::

    If you get an error that the `$authUtils` argument is missing, it's probably because you need
    to activate this new feature in Symfony 3.3. See this :ref:`controller service argument note <controller-service-arguments-tag>`.

What do you guys think about the wording? If we like it, we should really repeat this in other places.

[JasonBenett]

I totally agree with your wording. Less clumsy than mine!
Indeed, we can repeat this one on every page updated to use the autowire.

[OskarStark]

maybe behavior sounds more familar then comportment?

[JasonBenett]

@OskarStark yes you're right. My english skills are sometimes a little bit poor ;)
But my sentence should be replaced by the one given by @weaverryan so no problem

[xabbuh]

@JasonBenett Do you think you can make the change Ryan suggested? And possibly also add it in other places where we now make use of the controller being registered as a service.

[javiereguiluz]

@JasonBenett thanks for this contribution! Sadly, Symfony 3.3 was deprecated before we could merge this ... so I've opened #9235 to merge this in 3.4 branch instead. In any case, thanks for helping us realize that this needed further explanation!