Remove SendBeginFramesToChildren plumbing

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index a5df06a1144ae54cb280954158143eb7d96ee43c..5bf790e35cf000100055bb7ed2abba2acb92c37c 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -386,24 +386,6 @@ bool Compositor::HasAnimationObserver(
   return animation_observer_list_.HasObserver(observer);
 }
 
-void Compositor::AddBeginFrameObserver(CompositorBeginFrameObserver* observer) {
-  if (!begin_frame_observer_list_.might_have_observers())
-    host_->SetChildrenNeedBeginFrames(true);
-
-  begin_frame_observer_list_.AddObserver(observer);
-
-  if (missed_begin_frame_args_.IsValid())
-    observer->OnSendBeginFrame(missed_begin_frame_args_);
-}
-
-void Compositor::RemoveBeginFrameObserver(
-    CompositorBeginFrameObserver* observer) {
-  begin_frame_observer_list_.RemoveObserver(observer);
-
-  // As this call may take place while iterating over observers, unsubscription
-  // from |host_| is performed after iteration in |SendBeginFramesToChildren()|.
-}
-
 void Compositor::BeginMainFrame(const cc::BeginFrameArgs& args) {
   FOR_EACH_OBSERVER(CompositorAnimationObserver,
                     animation_observer_list_,
@@ -475,24 +457,6 @@ void Compositor::SetOutputIsSecure(bool output_is_secure) {
   host_->SetNeedsRedraw();
 }
 
-void Compositor::SendBeginFramesToChildren(const cc::BeginFrameArgs& args) {
-  FOR_EACH_OBSERVER(CompositorBeginFrameObserver, begin_frame_observer_list_,
-                    OnSendBeginFrame(args));
-
-  // Unsubscription is performed here, after iteration, to handle the case where
-  // the last BeginFrame observer is removed while iterating over the observers.
-  if (!begin_frame_observer_list_.might_have_observers()) {
-    host_->SetChildrenNeedBeginFrames(false);
-    // Unsubscription should reset |missed_begin_frame_args_|, avoiding stale
-    // BeginFrame dispatch when the next BeginFrame observer is added.
-    missed_begin_frame_args_ = cc::BeginFrameArgs();
-    return;
-  }
-
-  missed_begin_frame_args_ = args;
-  missed_begin_frame_args_.type = cc::BeginFrameArgs::MISSED;
-}
-
 const cc::LayerTreeDebugState& Compositor::GetLayerTreeDebugState() const {
   return host_->debug_state();
 }