[Gtk] allow building with css-shaders

https://bugs.webkit.org/show_bug.cgi?id=95603

Patch by Arnaud Renevier <a.renevier@sisa.samsung.com> on 2012-09-11
Reviewed by Martin Robinson.

.:

if unstable features and accelerated compositing are turned on, and
acceleration backend is opengl, then build CSS Shaders and CSS
Filters.

* configure.ac:

Source/WebCore:

Add support for css filters and shaders in GNUmakefile.am and include
Texture.cpp, Texture.h, TilingData.cpp and TilingData.h in
webcore_sources

No functional change, so no new tests.

* GNUmakefile.am:
* GNUmakefile.list.am:

Source/WebKit/gtk:

Add enable-css-shaders property to WebKit WebSettings, and connects it
to WebCore settings setCSSCustomFilterEnabled.

* webkit/webkitwebsettings.cpp:
(webkit_web_settings_class_init):
(webkit_web_settings_set_property):
(webkit_web_settings_get_property):
* webkit/webkitwebsettingsprivate.h:
* webkit/webkitwebview.cpp:
(webkit_web_view_update_settings):
(webkit_web_view_settings_notify):

git-svn-id: svn://svn.chromium.org/blink/trunk@128231 bbb929c8-8fbe-4397-9dbb-9b2b20218538