[ci skip] Remove comments about Rails 3.1

Stems from https://github.com/rails/rails/pull/20105#issuecomment-100900939
where @senny said:

> From my point of view, all the docs (guides, API) are version bound.
> They should describe that version and continue to be available when newer versions are released.
> The cross referencing can be done by the interested user.

1 files changed, 3 insertions, 3 deletions

diff --git a/actionpack/lib/action_controller/metal/streaming.rb b/actionpack/lib/action_controller/metal/streaming.rb
index 04401cad7b..af31de1f3a 100644
--- a/actionpack/lib/action_controller/metal/streaming.rb
+++ b/actionpack/lib/action_controller/metal/streaming.rb
@@ -110,9 +110,9 @@ module ActionController #:nodoc:
   # This means that, if you have <code>yield :title</code> in your layout
   # and you want to use streaming, you would have to render the whole template
   # (and eventually trigger all queries) before streaming the title and all
-  # assets, which kills the purpose of streaming. For this reason Rails 3.1
-  # introduces a new helper called +provide+ that does the same as +content_for+
-  # but tells the layout to stop searching for other entries and continue rendering.
+  # assets, which kills the purpose of streaming. For this purpose, you can use
+  # a helper called +provide+ that does the same as +content_for+ but tells the
+  # layout to stop searching for other entries and continue rendering.
   #
   # For instance, the template above using +provide+ would be:
   #