[GTK] Minibrowser : Add window fullscreen support for Minibrowser
https://bugs.webkit.org/show_bug.cgi?id=137775

Patch by Rohit Kumar <kumar.rohit@samsung.com> on 2014-10-30
Reviewed by Carlos Garcia Campos.

* MiniBrowser/gtk/BrowserWindow.c:
(toggleFullScreen): Callback to toggle window fullscreen on pressing F11 key.
(browser_window_init):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@175371 268f45cc-cd09-0410-ab3c-d52691b4dbfc