Move ReferencedSurfaceTracker into GpuCompositorFrameSink.

services/ui/surfaces/gpu_compositor_frame_sink.cc

Index: services/ui/surfaces/gpu_compositor_frame_sink.cc
diff --git a/services/ui/surfaces/gpu_compositor_frame_sink.cc b/services/ui/surfaces/gpu_compositor_frame_sink.cc
index 34ef009d4fd1206f85067b472a8321c400c702b3..0e1584f94e80ffb369c5c68aa56f3a592ad8c7a4 100644
--- a/services/ui/surfaces/gpu_compositor_frame_sink.cc
+++ b/services/ui/surfaces/gpu_compositor_frame_sink.cc
@@ -4,6 +4,7 @@
 
 #include "services/ui/surfaces/gpu_compositor_frame_sink.h"
 
+#include "cc/surfaces/surface_reference.h"
 #include "services/ui/surfaces/display_compositor.h"
 
 namespace ui {
@@ -24,6 +25,7 @@ GpuCompositorFrameSink::GpuCompositorFrameSink(
                frame_sink_id,
                std::move(display),
                std::move(begin_frame_source)),
+      surface_tracker_(frame_sink_id),
       client_(std::move(client)),
       binding_(this, std::move(request)),
       compositor_frame_sink_private_binding_(
@@ -38,7 +40,17 @@ GpuCompositorFrameSink::GpuCompositorFrameSink(
                  base::Unretained(this)));
 }
 
-GpuCompositorFrameSink::~GpuCompositorFrameSink() {}
+GpuCompositorFrameSink::~GpuCompositorFrameSink() {
+  // For display root surfaces, remove the reference from top level root to
+  // indicate the display root surface is no longer visible.
+  if (support_.display() && surface_tracker_.current_surface_id().is_valid()) {
+    const cc::SurfaceId top_level_root_surface_id =
+        display_compositor_->manager()->GetRootSurfaceId();
+    std::vector<cc::SurfaceReference> references_to_remove{cc::SurfaceReference(
+        top_level_root_surface_id, surface_tracker_.current_surface_id())};
+    display_compositor_->RemoveSurfaceReferences(references_to_remove);
+  }
+}
 
 void GpuCompositorFrameSink::EvictFrame() {
   support_.EvictFrame();
@@ -51,17 +63,41 @@ void GpuCompositorFrameSink::SetNeedsBeginFrame(bool needs_begin_frame) {
 void GpuCompositorFrameSink::SubmitCompositorFrame(
     const cc::LocalFrameId& local_frame_id,
     cc::CompositorFrame frame) {
-  support_.SubmitCompositorFrame(local_frame_id, std::move(frame));
-}
+  cc::SurfaceId start_surface_id = surface_tracker_.current_surface_id();
+  surface_tracker_.UpdateReferences(local_frame_id,
+                                    frame.metadata.referenced_surfaces);
 
-void GpuCompositorFrameSink::AddSurfaceReferences(
-    const std::vector<cc::SurfaceReference>& references) {
-  display_compositor_->AddSurfaceReferences(references);
-}
+  support_.SubmitCompositorFrame(local_frame_id, std::move(frame));
 
-void GpuCompositorFrameSink::RemoveSurfaceReferences(
-    const std::vector<cc::SurfaceReference>& references) {
-  display_compositor_->RemoveSurfaceReferences(references);
+  // Get the list of surfaces to add/remove from |surface_tracker_| so we can
+  // append to them before adding/removing.
+  std::vector<cc::SurfaceReference>& references_to_add =
+      surface_tracker_.references_to_add();
+  std::vector<cc::SurfaceReference>& references_to_remove =
+      surface_tracker_.references_to_remove();
+
+  // Append TLR references for the display root surfaces when display root
+  // surface changes.
+  if (support_.display() &&
+      start_surface_id != surface_tracker_.current_surface_id()) {
+    const cc::SurfaceId top_level_root_surface_id =
+        display_compositor_->manager()->GetRootSurfaceId();
+
+    // The first frame will not have a valid |start_surface_id| and there will
+    // be no surface to remove.
+    if (start_surface_id.local_frame_id().is_valid()) {
+      references_to_remove.push_back(
+          cc::SurfaceReference(top_level_root_surface_id, start_surface_id));
+    }
+
+    references_to_add.push_back(cc::SurfaceReference(
+        top_level_root_surface_id, surface_tracker_.current_surface_id()));
+  }
+
+  if (!references_to_add.empty())
+    display_compositor_->AddSurfaceReferences(references_to_add);
+  if (!references_to_remove.empty())
+    display_compositor_->RemoveSurfaceReferences(references_to_remove);
 }
 
 void GpuCompositorFrameSink::Require(const cc::LocalFrameId& local_frame_id,