cc: Introduce BeginFrame sequence numbers and acknowledgements.

cc/surfaces/compositor_frame_sink_support.cc

 // 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.
 
 #include "cc/surfaces/compositor_frame_sink_support.h"
 
 #include "cc/output/compositor_frame.h"
 #include "cc/scheduler/begin_frame_source.h"
 #include "cc/surfaces/compositor_frame_sink_support_client.h"
 #include "cc/surfaces/display.h"
@@ skipping 55 matching lines @@
       // TODO(piman, fsamuel): We will likely want to revisit this because some
       // clients may want finer control over the Display sizing - since it
       // really means the actual size of the native window (Linux/Win Aura) or
       // display (Ozone). We may need to either prevent or gutter Display frames
       // until there is a correctly-sized top-level CompositorFrame available
       // (see ui::Compositor::DisableSwapUntilResize). We might want to resize
       // Display earlier.
       display_->Resize(frame_size);
     }
   }
+
+  uint64_t begin_frame_source_id = frame.metadata.begin_frame_source_id;
+  uint64_t begin_frame_number = frame.metadata.begin_frame_number;
+  uint64_t latest_confirmed_frame = frame.metadata.latest_confirmed_frame;
   ++ack_pending_count_;
+
   surface_factory_.SubmitCompositorFrame(
       local_frame_id_, std::move(frame),
       base::Bind(&CompositorFrameSinkSupport::DidReceiveCompositorFrameAck,
                  weak_factory_.GetWeakPtr()));
   if (display_) {
     display_->SetLocalFrameId(local_frame_id_,
                               frame.metadata.device_scale_factor);
   }
+
+  BeginFrameAck ack(begin_frame_source_id, begin_frame_number,
+                    latest_confirmed_frame, 0, true);
+  if (begin_frame_source_)
+    begin_frame_source_->DidFinishFrame(this, ack);
+}
+
+void CompositorFrameSinkSupport::BeginFrameDidNotDraw(
+    const BeginFrameAck& ack) {
+  if (begin_frame_source_)
+    begin_frame_source_->DidFinishFrame(this, ack);
 }
 
 void CompositorFrameSinkSupport::Require(const LocalFrameId& local_frame_id,
                                          const SurfaceSequence& sequence) {
   Surface* surface = surface_manager_->GetSurfaceForId(
       SurfaceId(frame_sink_id_, local_frame_id));
   if (!surface) {
     DLOG(ERROR) << "Attempting to require callback on nonexistent surface";
     return;
   }
@@ skipping 96 matching lines @@
     return;
 
   added_frame_observer_ = needs_begin_frame_;
   if (needs_begin_frame_)
     begin_frame_source_->AddObserver(this);
   else
     begin_frame_source_->RemoveObserver(this);
 }
 
 }  // namespace cc