cc: Plumbing for BeginFrameSource based on Surfaces

cc/surfaces/display.cc

Index: cc/surfaces/display.cc
diff --git a/cc/surfaces/display.cc b/cc/surfaces/display.cc
index dd776fb1bc4d118408d8557c20a7b2eefc75389b..7cd9d6d126b566dd5547595523d92a181a2d466d 100644
--- a/cc/surfaces/display.cc
+++ b/cc/surfaces/display.cc
@@ -131,8 +131,8 @@ void Display::InitializeRenderer() {
   // overlays.
   bool output_partial_list = renderer_->Capabilities().using_partial_swap &&
                              !output_surface_->GetOverlayCandidateValidator();
-  aggregator_.reset(new SurfaceAggregator(manager_, resource_provider_.get(),
-                                          output_partial_list));
+  aggregator_.reset(new SurfaceAggregator(
+      this, manager_, resource_provider_.get(), output_partial_list));
 }
 
 void Display::DidLoseOutputSurface() {
@@ -150,6 +150,31 @@ void Display::UpdateRootSurfaceResourcesLocked() {
     scheduler_->SetRootSurfaceResourcesLocked(root_surface_resources_locked);
 }
 
+void Display::AddSurface(Surface* surface) {
+  // Checking for the output_surface ensures Display::Initialize has been
+  // called and that scheduler_ won't change its value.
+  DCHECK(output_surface_);
+
+  // WebView's HardwareRenderer will never have a scheduler.
+  if (!scheduler_)
+    return;
+
+  surface->AddBeginFrameSource(scheduler_->begin_frame_source_for_children());
+}
+
+void Display::RemoveSurface(Surface* surface) {
+  // Checking for the output_surface ensures Display::Initialize has been
+  // called and that scheduler_ won't change its value.
+  DCHECK(output_surface_);
+
+  // WebView's HardwareRenderer will never have a scheduler.
+  if (!scheduler_)
+    return;
+
+  surface->RemoveBeginFrameSource(
+      scheduler_->begin_frame_source_for_children());
+}
+
 bool Display::DrawAndSwap() {
   TRACE_EVENT0("cc", "Display::DrawAndSwap");