[GTK][Qt] Make compositing messages async again
https://bugs.webkit.org/show_bug.cgi?id=106082

Patch by Carlos Garcia Campos <cgarcia@igalia.com> on 2013-01-04
Reviewed by Simon Hausmann.

* UIProcess/WebPageProxy.cpp:
(WebKit::WebPageProxy::setComposition):
(WebKit::WebPageProxy::confirmComposition):
(WebKit::WebPageProxy::cancelComposition):
* WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::confirmComposition):
(WebKit::WebPage::setComposition):
(WebKit::WebPage::cancelComposition):
* WebProcess/WebPage/WebPage.h:
(WebPage):
* WebProcess/WebPage/WebPage.messages.in:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@138791 268f45cc-cd09-0410-ab3c-d52691b4dbfc