Refactor OverlayStrategySandwich and OverlayStrategyCommon

cc/output/overlay_strategy_underlay.h

Index: cc/output/overlay_strategy_underlay.h
diff --git a/cc/output/overlay_strategy_underlay.h b/cc/output/overlay_strategy_underlay.h
index 20c210697f5a364f706922739d632d1f26c31672..473e696b9ce37357e9f63c68edd65059fa586673 100644
--- a/cc/output/overlay_strategy_underlay.h
+++ b/cc/output/overlay_strategy_underlay.h
@@ -5,30 +5,29 @@
 #ifndef CC_OUTPUT_OVERLAY_STRATEGY_UNDERLAY_H_
 #define CC_OUTPUT_OVERLAY_STRATEGY_UNDERLAY_H_
 
-#include "cc/output/overlay_strategy_common.h"
+#include "cc/output/overlay_processor.h"
 
 namespace cc {
-class StreamVideoDrawQuad;
-class TextureDrawQuad;
+
+class OverlayCandidateValidator;
 
 // The underlay strategy looks for a video quad without regard to quads above
 // it. The video is "underlaid" through a black transparent quad substituted
 // for the video quad. The overlay content can then be blended in by the
 // hardware under the the scene. This is only valid for overlay contents that
 // are fully opaque.
-class CC_EXPORT OverlayStrategyUnderlay : public OverlayStrategyCommonDelegate {
+class CC_EXPORT OverlayStrategyUnderlay : public OverlayProcessor::Strategy {
  public:
-  OverlayStrategyUnderlay() {}
+  explicit OverlayStrategyUnderlay(
+      OverlayCandidateValidator* capability_checker);
   ~OverlayStrategyUnderlay() override;
 
-  OverlayResult TryOverlay(OverlayCandidateValidator* capability_checker,
-                           RenderPassList* render_passes_in_draw_order,
-                           OverlayCandidateList* candidate_list,
-                           const OverlayCandidate& candidate,
-                           QuadList::Iterator* candidate_iterator,
-                           float device_scale_factor) override;
+  bool Attempt(RenderPassList* render_passes,
+               OverlayCandidateList* candidate_list) override;
 
  private:
+  OverlayCandidateValidator* capability_checker_;  // Weak.
+
   DISALLOW_COPY_AND_ASSIGN(OverlayStrategyUnderlay);
 };