cc: Introduce BeginFrame sequence numbers and acknowledgements.

cc/output/software_renderer.cc

Index: cc/output/software_renderer.cc
diff --git a/cc/output/software_renderer.cc b/cc/output/software_renderer.cc
index c18e4def79e9edf799a2d3b5d057dab6c0a8d559..e9d61237b3689e8f748173e33097426a68d57460 100644
--- a/cc/output/software_renderer.cc
+++ b/cc/output/software_renderer.cc
@@ -80,11 +80,9 @@ void SoftwareRenderer::FinishDrawingFrame(DrawingFrame* frame) {
   output_device_->EndPaint();
 }
 
-void SoftwareRenderer::SwapBuffers(std::vector<ui::LatencyInfo> latency_info) {
+void SoftwareRenderer::SwapBuffers(OutputSurfaceFrame output_frame) {
   DCHECK(visible_);
   TRACE_EVENT0("cc", "SoftwareRenderer::SwapBuffers");
-  OutputSurfaceFrame output_frame;
-  output_frame.latency_info = std::move(latency_info);
   output_surface_->SwapBuffers(std::move(output_frame));
 }