[cc] Set BeginFrame sequence numbers on CompositorFrames from Scheduler.

cc/output/compositor_frame_metadata.h

 // Copyright (c) 2012 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_COMPOSITOR_FRAME_METADATA_H_
 #define CC_OUTPUT_COMPOSITOR_FRAME_METADATA_H_
 
 #include <stdint.h>
 
 #include <vector>
 
 #include "cc/base/cc_export.h"
 #include "cc/input/selection.h"
+#include "cc/output/begin_frame_args.h"
 #include "cc/surfaces/surface_id.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/events/latency_info.h"
 #include "ui/gfx/geometry/size_f.h"
 #include "ui/gfx/geometry/vector2d_f.h"
 #include "ui/gfx/selection_bound.h"
 
 namespace cc {
 
 class CC_EXPORT CompositorFrameMetadata {
@@ skipping 51 matching lines @@
 
   std::vector<ui::LatencyInfo> latency_info;
 
   // This is the set of Surfaces that are referenced by this frame.
   std::vector<SurfaceId> referenced_surfaces;
 
   // This indicates whether this CompositorFrame can be activated before
   // dependencies have been resolved.
   bool can_activate_before_dependencies = true;
 
+  // Source identifier and sequence number of the BeginFrame that this
+  // CompositorFrame is in response to and sequence number that it confirms.
+  uint32_t begin_frame_source_id = 0;
+  uint64_t begin_frame_sequence_number = BeginFrameArgs::kInvalidFrameNumber;
+  uint64_t latest_confirmed_begin_frame_sequence_number =
+      BeginFrameArgs::kInvalidFrameNumber;

[brianderson, 2017/02/24 01:08:36]

Can this be an instance of the BeginFrameAck struct?

[Eric Seckler, 2017/02/27 11:50:32]

Done. Was trying to avoid overhead of the unused fields (remaining_frames and
has_damage), but it does look nicer having an ACK in here, and the overhead
should be minimal. And remaining_frames should go away eventually.

+
  private:
   CompositorFrameMetadata(const CompositorFrameMetadata& other);
   CompositorFrameMetadata operator=(const CompositorFrameMetadata&) = delete;
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_COMPOSITOR_FRAME_METADATA_H_