Add DCLayerOverlayProcessor and supporting DCLayer structures.

components/display_compositor/compositor_overlay_candidate_validator_ozone.h

 // 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.
 
 #ifndef COMPONENTS_DISPLAY_COMPOSITOR_COMPOSITOR_OVERLAY_CANDIDATE_VALIDATOR_OZONE_H_
 #define COMPONENTS_DISPLAY_COMPOSITOR_COMPOSITOR_OVERLAY_CANDIDATE_VALIDATOR_OZONE_H_
 
 #include <memory>
 
 #include "base/callback.h"
@@ skipping 12 matching lines @@
     : public CompositorOverlayCandidateValidator {
  public:
   CompositorOverlayCandidateValidatorOzone(
       std::unique_ptr<ui::OverlayCandidatesOzone> overlay_candidates,
       std::string strategies_string);
   ~CompositorOverlayCandidateValidatorOzone() override;
 
   // cc::OverlayCandidateValidator implementation.
   void GetStrategies(cc::OverlayProcessor::StrategyList* strategies) override;
   bool AllowCALayerOverlays() override;
+  bool AllowDCLayerOverlays() override;
   void CheckOverlaySupport(cc::OverlayCandidateList* surfaces) override;
 
   // CompositorOverlayCandidateValidator implementation.
   void SetSoftwareMirrorMode(bool enabled) override;
 
  private:
   std::unique_ptr<ui::OverlayCandidatesOzone> overlay_candidates_;
   // Callback declaration to allocate a new OverlayProcessor::Strategy.
   using StrategyInstantiator =
       base::Callback<std::unique_ptr<cc::OverlayProcessor::Strategy>(
           CompositorOverlayCandidateValidatorOzone*)>;
   // List callbacks used to instantiate OverlayProcessor::Strategy
   // as defined by |strategies_string| paramter in the constructor.
   std::vector<StrategyInstantiator> strategies_instantiators_;
   bool software_mirror_active_;
 
   DISALLOW_COPY_AND_ASSIGN(CompositorOverlayCandidateValidatorOzone);
 };
 
 }  // namespace display_compositor
 
 #endif  // COMPONENTS_DISPLAY_COMPOSITOR_COMPOSITOR_OVERLAY_CANDIDATE_VALIDATOR_OZONE_H_