Mac: Use AVSampleBufferDisplayLayer for 4:2:0 surfaces

content/common/gpu/ca_layer_tree_mac.h

 // Copyright 2016 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 CONTENT_COMMON_GPU_CA_LAYER_TREE_MAC_H_
 #define CONTENT_COMMON_GPU_CA_LAYER_TREE_MAC_H_
 
 #include <IOSurface/IOSurface.h>
 #include <QuartzCore/QuartzCore.h>
 #include <deque>
 #include <vector>
 
 #include "base/mac/scoped_cftyperef.h"
 #include "base/mac/scoped_nsobject.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/common/content_export.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/transform.h"
 
+@class AVSampleBufferDisplayLayer;
+
 namespace content {
 
 // The CALayerTree will construct a hierarchy of CALayers from a linear list,
 // using the algorithm and structure referenced described in
 // https://docs.google.com/document/d/1DtSN9zzvCF44_FQPM7ie01UxGHagQ66zfF5L9HnigQY/edit?usp=sharing
 class CONTENT_EXPORT CALayerTree {
  public:
   CALayerTree();
 
   // This will remove all CALayers from this tree from their superlayer.
@@ skipping 136 matching lines @@
     const base::ScopedCFTypeRef<IOSurfaceRef> io_surface;
     gfx::RectF contents_rect;
     gfx::Rect rect;
     unsigned background_color = 0;
     // Note that the CoreAnimation edge antialiasing mask is not the same as
     // the edge antialiasing mask passed to the constructor.
     CAEdgeAntialiasingMask ca_edge_aa_mask = 0;
     float opacity = 1;
     base::scoped_nsobject<CALayer> ca_layer;
 
+    // If this layer's contents can be represented as an
+    // AVSampleBufferDisplayLayer, then |ca_layer| will point to |av_layer|.
+    base::scoped_nsobject<AVSampleBufferDisplayLayer> av_layer;
+    bool use_av_layer = false;
+
    private:
     DISALLOW_COPY_AND_ASSIGN(ContentLayer);
   };
 
   RootLayer root_layer_;
   float scale_factor_ = 1;
   bool has_committed_ = false;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(CALayerTree);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_COMMON_GPU_CA_LAYER_TREE_MAC_H_