Mac Overlays: Add sandwich strategy

cc/output/overlay_strategy_underlay.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/output/overlay_strategy_underlay.h"
 
 #include "cc/output/overlay_candidate_validator.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/quads/solid_color_draw_quad.h"
 
 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;
 
   // Add our primary surface.
   OverlayCandidateList candidates;
   OverlayCandidate main_image;
   main_image.display_rect = root_render_pass->output_rect;
   candidates.push_back(main_image);
 
   // Add the overlay.
@@ skipping 14 matching lines @@
             candidate_iterator);
     replacement->SetAll(shared_quad_state, rect, rect, rect, false,
                         SK_ColorTRANSPARENT, true);
     candidate_list->swap(candidates);
     return true;
   }
   return false;
 }
 
 }  // namespace cc