FrameGenerator should receive SurfaceInfo and use it in frame generation

services/ui/ws/frame_generator.cc

Index: services/ui/ws/frame_generator.cc
diff --git a/services/ui/ws/frame_generator.cc b/services/ui/ws/frame_generator.cc
index 114af93278c4e08ac9226f8cb2db900e378ae173..1e58213b2c42c6da98cd357a122c2e5b7845fafb 100644
--- a/services/ui/ws/frame_generator.cc
+++ b/services/ui/ws/frame_generator.cc
@@ -46,23 +46,19 @@ void FrameGenerator::OnAcceleratedWidgetAvailable(
   root_window_->CreateDisplayCompositorFrameSink(
       widget, std::move(request), binding_.CreateInterfacePtrAndBind(),
       std::move(display_private_request));
-  // TODO(fsamuel): This means we're always requesting a new BeginFrame signal
-  // even when we don't need it. Once surface ID propagation work is done,
-  // this will not be necessary because FrameGenerator will only need a
-  // BeginFrame if the window manager changes.
-  compositor_frame_sink_->SetNeedsBeginFrame(true);
 }
 
-void FrameGenerator::OnSurfaceCreated(const cc::SurfaceId& surface_id,
-                                      ServerWindow* window) {
-  DCHECK(surface_id.is_valid());
+void FrameGenerator::OnSurfaceCreated(const cc::SurfaceInfo& surface_info) {
+  DCHECK(surface_info.id().is_valid());
 
   // Only handle embedded surfaces changing here. The display root surface
   // changing is handled immediately after the CompositorFrame is submitted.
   // TODO(samans): Only tell FrameGenerator about WM surface instead of all
   // all surfaces.
-  if (window == delegate_->GetActiveRootWindow())
-    window_manager_surface_id_ = surface_id;
+  if (surface_info != window_manager_surface_info_) {
+    compositor_frame_sink_->SetNeedsBeginFrame(true);
+    window_manager_surface_info_ = surface_info;
+  }
 }
 
 void FrameGenerator::DidReceiveCompositorFrameAck() {}
@@ -84,6 +80,7 @@ void FrameGenerator::OnBeginFrame(const cc::BeginFrameArgs& begin_frame_arags) {
 
     compositor_frame_sink_->SubmitCompositorFrame(local_frame_id_,
                                                   std::move(frame));
+    compositor_frame_sink_->SetNeedsBeginFrame(false);
     last_submitted_frame_size_ = frame_size;
   }
 }
@@ -127,8 +124,10 @@ cc::CompositorFrame FrameGenerator::GenerateCompositorFrame(
   }
   frame.metadata.device_scale_factor = device_scale_factor_;
 
-  if (window_manager_surface_id_.is_valid())
-    frame.metadata.referenced_surfaces.push_back(window_manager_surface_id_);
+  if (window_manager_surface_info_.id().is_valid()) {
+    frame.metadata.referenced_surfaces.push_back(
+        window_manager_surface_info_.id());
+  }
 
   return frame;
 }