Refactor OverlayStrategySandwich and OverlayStrategyCommon

cc/output/overlay_strategy_single_on_top.h

Index: cc/output/overlay_strategy_single_on_top.h
diff --git a/cc/output/overlay_strategy_single_on_top.h b/cc/output/overlay_strategy_single_on_top.h
index 17c763d8896e6201c088952406011b0dce7b345e..e2991e48db42fda7f1f696de6b11eedc3c1c5cb5 100644
--- a/cc/output/overlay_strategy_single_on_top.h
+++ b/cc/output/overlay_strategy_single_on_top.h
@@ -5,32 +5,29 @@
 #ifndef CC_OUTPUT_OVERLAY_STRATEGY_SINGLE_ON_TOP_H_
 #define CC_OUTPUT_OVERLAY_STRATEGY_SINGLE_ON_TOP_H_
 
-#include "base/basictypes.h"
-#include "base/memory/scoped_ptr.h"
-#include "cc/base/cc_export.h"
-#include "cc/output/overlay_candidate.h"
 #include "cc/output/overlay_processor.h"
-#include "cc/output/overlay_strategy_common.h"
-#include "cc/quads/render_pass.h"
 
 namespace cc {
-class StreamVideoDrawQuad;
-class TextureDrawQuad;
 
-class CC_EXPORT OverlayStrategySingleOnTop
-    : public OverlayStrategyCommonDelegate {
+class OverlayCandidateValidator;
+
+class CC_EXPORT OverlayStrategySingleOnTop : public OverlayProcessor::Strategy {
  public:
-  OverlayStrategySingleOnTop() {}
+  explicit OverlayStrategySingleOnTop(
+      OverlayCandidateValidator* capability_checker);
   ~OverlayStrategySingleOnTop() 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:
+  bool TryOverlay(QuadList& quad_list,
+                  OverlayCandidateList* candidate_list,
+                  const OverlayCandidate& candidate,
+                  QuadList::Iterator candidate_iterator);
+
+  OverlayCandidateValidator* capability_checker_;  // Weak.
+
   DISALLOW_COPY_AND_ASSIGN(OverlayStrategySingleOnTop);
 };