Allow CopyOutputRequests on all render passes of a surface

cc/surfaces/surface.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_H_
 #define CC_SURFACES_SURFACE_H_
 
 #include <vector>
 
 #include "base/callback.h"
@@ skipping 21 matching lines @@
  public:
   Surface(SurfaceId id, const gfx::Size& size, SurfaceFactory* factory);
   ~Surface();
 
   const gfx::Size& size() const { return size_; }
   SurfaceId surface_id() const { return surface_id_; }
 
   void QueueFrame(scoped_ptr<CompositorFrame> frame,
                   const base::Closure& draw_callback);
   void RequestCopyOfOutput(scoped_ptr<CopyOutputRequest> copy_request);
+  // Modifies copy_requests to have a ScopedPtrVector for each render pass in
+  // the current frame, containing all the copy requests from pass.
   void TakeCopyOutputRequests(
-      ScopedPtrVector<CopyOutputRequest>* copy_requests);
+      ScopedPtrVector<ScopedPtrVector<CopyOutputRequest>>* copy_requests);

[jamesr, 2014/10/15 03:21:39]

why's this a pointer to a vector of pointers of vectors of pointers?

if this is intended to be sparse, instead of passing piles of NULLs can we pass
a list of tuples of CopyOutputRequest, pass id, quad ids?  there should be 0 or
1 entry in this in the average case

   // Returns the most recent frame that is eligible to be rendered.
   const CompositorFrame* GetEligibleFrame();
 
   // Returns a number that increments by 1 every time a new frame is enqueued.
   int frame_index() const { return frame_index_; }
 
   void TakeLatencyInfo(std::vector<ui::LatencyInfo>* latency_info);
   void RunDrawCallbacks();
 
   SurfaceFactory* factory() { return factory_; }
 
  private:
+  void ClearCopyRequests();
+
   SurfaceId surface_id_;
   gfx::Size size_;
   SurfaceFactory* factory_;
   // TODO(jamesr): Support multiple frames in flight.
   scoped_ptr<CompositorFrame> current_frame_;
   int frame_index_;
-  ScopedPtrVector<CopyOutputRequest> copy_requests_;
 
   base::Closure draw_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(Surface);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_H_