[GTK] build fails with error: cannot allocate an object of abstract type 'WebKit::PageClientImpl'
https://bugs.webkit.org/show_bug.cgi?id=136017

Patch by Byungseon Shin <sun.shin@lge.com> on 2014-08-16
Reviewed by Gyuyoung Kim.

* UIProcess/API/gtk/PageClientImpl.cpp:
(WebKit::PageClientImpl::didFirstVisuallyNonEmptyLayoutForMainFrame):
(WebKit::PageClientImpl::didFinishLoadForMainFrame):
* UIProcess/API/gtk/PageClientImpl.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@172690 268f45cc-cd09-0410-ab3c-d52691b4dbfc