[Qt] Animated opacity does not trigger accelerated compositing
https://bugs.webkit.org/show_bug.cgi?id=115107

Reviewed by Simon Fraser.

Source/WebCore:

Add extra option to also trigger compositing on animated opacity.

* page/ChromeClient.h:
* rendering/RenderLayerCompositor.cpp:
(WebCore::RenderLayerCompositor::requiresCompositingForAnimation):

Source/WebKit/qt:

We should trigger compositing on animated opacity as it is always faster on Qt.

* WebCoreSupport/ChromeClientQt.cpp:
VideoTrigger removed because we have already disabled AC for video in qwebsettings.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@149123 268f45cc-cd09-0410-ab3c-d52691b4dbfc