[cc] Remove BeginFrameAck from BFS::DidFinishFrame and update tests.

cc/surfaces/display_scheduler.cc

Index: cc/surfaces/display_scheduler.cc
diff --git a/cc/surfaces/display_scheduler.cc b/cc/surfaces/display_scheduler.cc
index 40e80bf97bd36034d435bbe34c3b4242295cccd4..81483524e092fa6592d1f9b17ed241762878322b 100644
--- a/cc/surfaces/display_scheduler.cc
+++ b/cc/surfaces/display_scheduler.cc
@@ -364,11 +364,8 @@ void DisplayScheduler::OnBeginFrameDeadline() {
 }
 
 void DisplayScheduler::DidFinishFrame(bool did_draw) {
-  // TODO(eseckler): Determine and set correct |ack.latest_confirmed_frame|.
-  BeginFrameAck ack(current_begin_frame_args_.source_id,
-                    current_begin_frame_args_.sequence_number,
-                    current_begin_frame_args_.sequence_number, did_draw);
-  begin_frame_source_->DidFinishFrame(this, ack);
+  // TODO(eseckler): Let client know that frame was completed.

[sunnyps, 2017/05/24 02:38:26]

nit: DCHECK(begin_frame_source_) here

[Eric Seckler, 2017/05/24 09:00:40]

Done.

+  begin_frame_source_->DidFinishFrame(this);
 }
 
 void DisplayScheduler::DidSwapBuffers() {