Getting rid of DelegatedFrameData

cc/surfaces/surface.h

Index: cc/surfaces/surface.h
diff --git a/cc/surfaces/surface.h b/cc/surfaces/surface.h
index ad29d8142747f94f6ef7d05eddf541faaf72b697..a6a225e2d66dc96f1fa99264b6fea4bdc5b5741e 100644
--- a/cc/surfaces/surface.h
+++ b/cc/surfaces/surface.h
@@ -17,6 +17,7 @@
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "base/optional.h"
 #include "cc/output/copy_output_request.h"
 #include "cc/quads/render_pass_id.h"
 #include "cc/surfaces/frame_sink_id.h"
@@ -52,6 +53,7 @@ class CC_SURFACES_EXPORT Surface {
   void SetPreviousFrameSurface(Surface* surface);
 
   void QueueFrame(CompositorFrame frame, const DrawCallback& draw_callback);
+  void EvictFrame();
   void RequestCopyOfOutput(std::unique_ptr<CopyOutputRequest> copy_request);
   // Adds each CopyOutputRequest in the current frame to copy_requests. The
   // caller takes ownership of them.
@@ -60,8 +62,7 @@ class CC_SURFACES_EXPORT Surface {
           copy_requests);
 
   // Returns the most recent frame that is eligible to be rendered.
-  // If the CompositorFrame's DelegateFrameData is null then there is
-  // no eligible frame.
+  // You must check whether HasFrame() returns true before calling this method.
   const CompositorFrame& GetEligibleFrame();
 
   // Returns a number that increments by 1 every time a new frame is enqueued.
@@ -89,18 +90,20 @@ class CC_SURFACES_EXPORT Surface {
     return referenced_surfaces_;
   }
 
+  bool HasFrame() const { return current_frame_.has_value(); }
+
   bool destroyed() const { return destroyed_; }
   void set_destroyed(bool destroyed) { destroyed_ = destroyed; }
 
  private:
-  void UnrefFrameResources(DelegatedFrameData* frame_data);
+  void UnrefFrameResources(const CompositorFrame& frame_data);
   void ClearCopyRequests();
 
   SurfaceId surface_id_;
   SurfaceId previous_frame_surface_id_;
   base::WeakPtr<SurfaceFactory> factory_;
   // TODO(jamesr): Support multiple frames in flight.
-  CompositorFrame current_frame_;
+  base::Optional<CompositorFrame> current_frame_;
   int frame_index_;
   bool destroyed_;
   std::vector<SurfaceSequence> destruction_dependencies_;