GTK: Remove calls that no longer exist and just call the base unref.

webkit/glue/webcursor_gtk.cc

Index: webkit/glue/webcursor_gtk.cc
diff --git a/webkit/glue/webcursor_gtk.cc b/webkit/glue/webcursor_gtk.cc
index ce23ea8d1bb5c96115aa740a665daad6a11efc16..9b084412f42a7f2bed8a110338181069bf2df74c 100644
--- a/webkit/glue/webcursor_gtk.cc
+++ b/webkit/glue/webcursor_gtk.cc
@@ -182,10 +182,10 @@ GdkCursor* WebCursor::GetCustomCursor() {
                                                  hotspot_.x(),
                                                  hotspot_.y());
 
-  gdk_pixbuf_unref(pixbuf);
+  g_object_unref(pixbuf);
 
   if (unref_)
-    gdk_cursor_unref(unref_);
+    g_object_unref(unref_);
   unref_ = cursor;
   return cursor;
 }