Refactor OverlayStrategySandwich and OverlayStrategyCommon

cc/output/overlay_candidate.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 CC_OUTPUT_OVERLAY_CANDIDATE_H_
 #define CC_OUTPUT_OVERLAY_CANDIDATE_H_
 
 #include <vector>
 
 #include "cc/base/cc_export.h"
@@ skipping 13 matching lines @@
 class DrawQuad;
 class IOSurfaceDrawQuad;
 class StreamVideoDrawQuad;
 class TextureDrawQuad;
 
 class CC_EXPORT OverlayCandidate {
  public:
   // Returns true and fills in |candidate| if |draw_quad| is of a known quad
   // type and contains an overlayable resource.
   static bool FromDrawQuad(const DrawQuad* quad, OverlayCandidate* candidate);
+  // Returns true if |quad| will not block quads underneath from becoming
+  // an overlay.
+  static bool IsInvisibleQuad(const DrawQuad* quad);
+
   OverlayCandidate();
   ~OverlayCandidate();
 
   // Transformation to apply to layer during composition.
   gfx::OverlayTransform transform;
   // Format of the buffer to composite.
   ResourceFormat format;
   // Size of the resource, in pixels.
   gfx::Size resource_size_in_pixels;
   // Rect on the display to position the overlay to. Implementer must convert
@@ skipping 27 matching lines @@
                                   OverlayCandidate* candidate);
   static bool FromIOSurfaceQuad(const IOSurfaceDrawQuad* quad,
                                 OverlayCandidate* candidate);
 };
 
 typedef std::vector<OverlayCandidate> OverlayCandidateList;
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_OVERLAY_CANDIDATE_H_