List all child surfaces (including occluded) in CompositorFrame

cc/surfaces/surface_aggregator.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_SURFACES_SURFACE_AGGREGATOR_H_
 #define CC_SURFACES_SURFACE_AGGREGATOR_H_
 
 #include <set>
 
 #include "base/containers/hash_tables.h"
@@ skipping 42 matching lines @@
  private:
   struct ClipData {
     ClipData() : is_clipped(false) {}
     ClipData(bool is_clipped, const gfx::Rect& rect)
         : is_clipped(is_clipped), rect(rect) {}
 
     bool is_clipped;
     gfx::Rect rect;
   };
 
+  struct PrewalkResult {
+    PrewalkResult();

[danakj, 2015/11/16 21:45:46]

do you need a non-default constructor/destructor here?

+    ~PrewalkResult();
+    bool has_copy_requests;

[danakj, 2015/11/16 21:45:46]

could you just = false here instead of constructor?

+    // This is the set of Surfaces that were referenced by another Surface, but
+    // not included in a SurfaceDrawQuad.
+    std::set<SurfaceId> undrawn_surfaces;
+  };
+
   ClipData CalculateClipRect(const ClipData& surface_clip,
                              const ClipData& quad_clip,
                              const gfx::Transform& target_transform);
 
   RenderPassId RemapPassId(RenderPassId surface_local_pass_id,
                            SurfaceId surface_id);
 
   void HandleSurfaceQuad(const SurfaceDrawQuad* surface_quad,
                          const gfx::Transform& target_transform,
                          const ClipData& clip_rect,
                          RenderPass* dest_pass);
   SharedQuadState* CopySharedQuadState(const SharedQuadState* source_sqs,
                                        const gfx::Transform& target_transform,
                                        const ClipData& clip_rect,
                                        RenderPass* dest_render_pass);
   void CopyQuadsToPass(
       const QuadList& source_quad_list,
       const SharedQuadStateList& source_shared_quad_state_list,
       const base::hash_map<ResourceId, ResourceId>& resource_to_child_map,
       const gfx::Transform& target_transform,
       const ClipData& clip_rect,
       RenderPass* dest_pass,
       SurfaceId surface_id);
-  gfx::Rect PrewalkTree(SurfaceId surface_id);
+  gfx::Rect PrewalkTree(SurfaceId surface_id, PrewalkResult* result);
+  void CopyUnreferencedSurfaces(PrewalkResult* prewalk);
   void CopyPasses(const DelegatedFrameData* frame_data, Surface* surface);
 
   // Remove Surfaces that were referenced before but aren't currently
   // referenced from the ResourceProvider.
   // Also notifies SurfaceAggregatorClient of newly added and removed
   // child surfaces.
   void ProcessAddedAndRemovedSurfaces();
 
   int ChildIdForSurface(Surface* surface);
   gfx::Rect DamageRectForSurface(const Surface* surface,
@@ skipping 43 matching lines @@
 
   // Resource list for the aggregated frame.
   TransferableResourceArray* dest_resource_list_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfaceAggregator);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_AGGREGATOR_H_