[webkit-gtk] Add API for disabling the accelerated compositing

[Tomas Popela]

Hi everyone,

I would like to start a discussion about adding a new API for disabling
the accelerated compositing (AC). We (Evolution) actually don't need AC
enabled at all for our WebKitGTK+ use and some of our users are
observing a big performance hit with 2.14.x (please see [0]) that is
solved by disabling AC.

The only way right now to disable the AC is through the environment
variable WEBKIT_DISABLE_COMPOSITING_MODE. I would like to propose the
following API:

void webkit_web_context_set_accelerated_compositing_enabled (WebKitWebContext *context, gboolean enabled);

gboolean webkit_web_context_get_accelerated_compositing_enabled (WebKitWebContext *context);

As Carlos mentioned to me on IRC some people actually wanted to remove
the non AC mode for WebKitGTK+ at some point in the future. If so can
you please share the reasons with me (I have to admit that I remember
that someone mentioned that during the hackfest, but I don't recall
anything about that).

[0] - https://bugzilla.gnome.org/show_bug.cgi?id=774067

Tom