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

cc/trees/layer_tree_host_impl.cc

Index: cc/trees/layer_tree_host_impl.cc
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index 5be3b302c10cffea830b0de76551dc7391ede8b3..8f6491a9d9d93ef6285c6b890e781e155cccd349 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -179,7 +179,11 @@ DEFINE_SCOPED_UMA_HISTOGRAM_TIMER(PendingTreeDurationHistogramTimer,
 LayerTreeHostImpl::FrameData::FrameData()
     : render_surface_layer_list(nullptr),
       has_no_damage(false),
-      may_contain_video(false) {}
+      may_contain_video(false),
+      begin_frame_source_id(0),
+      begin_frame_sequence_number(BeginFrameArgs::kInvalidFrameNumber),
+      latest_confirmed_begin_frame_sequence_number(
+          BeginFrameArgs::kInvalidFrameNumber) {}
 
 LayerTreeHostImpl::FrameData::~FrameData() {}
 
@@ -1698,6 +1702,13 @@ bool LayerTreeHostImpl::DrawLayers(FrameData* frame) {
     }
   }
 
+  DCHECK_LE(BeginFrameArgs::kStartingFrameNumber,
+            frame->begin_frame_sequence_number);
+  metadata.begin_frame_source_id = frame->begin_frame_source_id;
+  metadata.begin_frame_sequence_number = frame->begin_frame_sequence_number;
+  metadata.latest_confirmed_begin_frame_sequence_number =
+      frame->latest_confirmed_begin_frame_sequence_number;
+
   CompositorFrame compositor_frame;
   compositor_frame.metadata = std::move(metadata);
   resource_provider_->PrepareSendToParent(resources,