Mac Overlays: Add sandwich strategy

cc/output/overlay_strategy_underlay.cc

Index: cc/output/overlay_strategy_underlay.cc
diff --git a/cc/output/overlay_strategy_underlay.cc b/cc/output/overlay_strategy_underlay.cc
index dd2b90f48146e30bd8de481e21cf8ac63129b783..67cd77d4cd1f2b75f60a7049c259587e1a1b7634 100644
--- a/cc/output/overlay_strategy_underlay.cc
+++ b/cc/output/overlay_strategy_underlay.cc
@@ -10,18 +10,15 @@
 
 namespace cc {
 
-OverlayStrategyUnderlay::OverlayStrategyUnderlay(
-    OverlayCandidateValidator* capability_checker)
-    : OverlayStrategyCommon(capability_checker) {
-}
+OverlayStrategyUnderlay::~OverlayStrategyUnderlay() {}
 
 bool OverlayStrategyUnderlay::TryOverlay(
     OverlayCandidateValidator* capability_checker,
-
     RenderPassList* render_passes_in_draw_order,
     OverlayCandidateList* candidate_list,
     const OverlayCandidate& candidate,
-    QuadList::Iterator candidate_iterator) {
+    QuadList::Iterator candidate_iterator,
+    float device_scale_factor) {
   RenderPass* root_render_pass = render_passes_in_draw_order->back();
   QuadList& quad_list = root_render_pass->quad_list;