[GTK] Clean up the WebKit build from unused parameter warning in Webkit2/UIProcess module
https://bugs.webkit.org/show_bug.cgi?id=136670

Patch by Rohit Kumar <kumar.rohit@samsung.com> on 2014-09-10
Reviewed by Martin Robinson.

* UIProcess/API/gtk/PageClientImpl.cpp:
(WebKit::PageClientImpl::didSameDocumentNavigationForMainFrame):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@173455 268f45cc-cd09-0410-ab3c-d52691b4dbfc