WebContent: Set correct scroll offset for PageHost painting

Author: https://github.com/speles
Commit: https://github.com/SerenityOS/serenity/commit/e97865e9828
Pull-request: https://github.com/SerenityOS/serenity/pull/5658
Issue: https://github.com/SerenityOS/serenity/issues/5336

Userland/Services/WebContent/PageHost.cpp

@@ -92,7 +92,7 @@ void PageHost::paint(const Gfx::IntRect& content_rect, Gfx::Bitmap& target)
 
     painter.translate(-content_rect.x(), -content_rect.y());
 
-    Web::PaintContext context(painter, palette(), Gfx::IntPoint());
+    Web::PaintContext context(painter, palette(), content_rect.top_left());
     context.set_should_show_line_box_borders(m_should_show_line_box_borders);
     context.set_viewport_rect(content_rect);
     layout_root->paint_all_phases(context);