diff --git a/shell/common/animator.cc b/shell/common/animator.cc
index fc30d49e1dda7..727d521b7184f 100644
--- a/shell/common/animator.cc
+++ b/shell/common/animator.cc
@@ -103,7 +103,7 @@ void Animator::BeginFrame(fml::TimePoint frame_start_time,
   {
     TRACE_EVENT2("flutter", "Framework Workload", "mode", "basic", "frame",
                  FrameParity());
-    delegate_.OnAnimatorBeginFrame(*this, last_begin_frame_time_);
+    delegate_.OnAnimatorBeginFrame(last_begin_frame_time_);
   }
 
   if (!frame_scheduled_) {
@@ -124,8 +124,8 @@ void Animator::BeginFrame(fml::TimePoint frame_start_time,
           // no further frames were produced, and it is safe (w.r.t. jank) to
           // notify the engine we are idle.
           if (notify_idle_task_id == self->notify_idle_task_id_) {
-            self->delegate_.OnAnimatorNotifyIdle(
-                *self.get(), Dart_TimelineGetMicros() + 100000);
+            self->delegate_.OnAnimatorNotifyIdle(Dart_TimelineGetMicros() +
+                                                 100000);
           }
         },
         kNotifyIdleTaskWaitTime);
@@ -148,7 +148,7 @@ void Animator::Render(std::unique_ptr<flow::LayerTree> layer_tree) {
   // Commit the pending continuation.
   producer_continuation_.Complete(std::move(layer_tree));
 
-  delegate_.OnAnimatorDraw(*this, layer_tree_pipeline_);
+  delegate_.OnAnimatorDraw(layer_tree_pipeline_);
 }
 
 bool Animator::CanReuseLastLayerTree() {
@@ -157,7 +157,7 @@ bool Animator::CanReuseLastLayerTree() {
 
 void Animator::DrawLastLayerTree() {
   pending_frame_semaphore_.Signal();
-  delegate_.OnAnimatorDrawLastLayerTree(*this);
+  delegate_.OnAnimatorDrawLastLayerTree();
 }
 
 void Animator::RequestFrame(bool regenerate_layer_tree) {
@@ -205,7 +205,7 @@ void Animator::AwaitVSync() {
         }
       });
 
-  delegate_.OnAnimatorNotifyIdle(*this, dart_frame_deadline_);
+  delegate_.OnAnimatorNotifyIdle(dart_frame_deadline_);
 }
 
 }  // namespace shell
diff --git a/shell/common/animator.h b/shell/common/animator.h
index ec8afea5503e6..470f04b542881 100644
--- a/shell/common/animator.h
+++ b/shell/common/animator.h
@@ -20,17 +20,14 @@ class Animator final {
  public:
   class Delegate {
    public:
-    virtual void OnAnimatorBeginFrame(const Animator& animator,
-                                      fml::TimePoint frame_time) = 0;
+    virtual void OnAnimatorBeginFrame(fml::TimePoint frame_time) = 0;
 
-    virtual void OnAnimatorNotifyIdle(const Animator& animator,
-                                      int64_t deadline) = 0;
+    virtual void OnAnimatorNotifyIdle(int64_t deadline) = 0;
 
     virtual void OnAnimatorDraw(
-        const Animator& animator,
         fml::RefPtr<flutter::Pipeline<flow::LayerTree>> pipeline) = 0;
 
-    virtual void OnAnimatorDrawLastLayerTree(const Animator& animator) = 0;
+    virtual void OnAnimatorDrawLastLayerTree() = 0;
   };
 
   Animator(Delegate& delegate,
diff --git a/shell/common/engine.cc b/shell/common/engine.cc
index 3c4bc493f1ec7..1b9d3657b6ece 100644
--- a/shell/common/engine.cc
+++ b/shell/common/engine.cc
@@ -385,8 +385,7 @@ void Engine::Render(std::unique_ptr<flow::LayerTree> layer_tree) {
 
 void Engine::UpdateSemantics(blink::SemanticsNodeUpdates update,
                              blink::CustomAccessibilityActionUpdates actions) {
-  delegate_.OnEngineUpdateSemantics(*this, std::move(update),
-                                    std::move(actions));
+  delegate_.OnEngineUpdateSemantics(std::move(update), std::move(actions));
 }
 
 void Engine::HandlePlatformMessage(
@@ -394,7 +393,7 @@ void Engine::HandlePlatformMessage(
   if (message->channel() == kAssetChannel) {
     HandleAssetPlatformMessage(std::move(message));
   } else {
-    delegate_.OnEngineHandlePlatformMessage(*this, std::move(message));
+    delegate_.OnEngineHandlePlatformMessage(std::move(message));
   }
 }
 
diff --git a/shell/common/engine.h b/shell/common/engine.h
index 2dfe73b78bd35..259f73514b67d 100644
--- a/shell/common/engine.h
+++ b/shell/common/engine.h
@@ -32,12 +32,10 @@ class Engine final : public blink::RuntimeDelegate {
   class Delegate {
    public:
     virtual void OnEngineUpdateSemantics(
-        const Engine& engine,
         blink::SemanticsNodeUpdates update,
         blink::CustomAccessibilityActionUpdates actions) = 0;
 
     virtual void OnEngineHandlePlatformMessage(
-        const Engine& engine,
         fml::RefPtr<blink::PlatformMessage> message) = 0;
 
     virtual void OnPreEngineRestart() = 0;
diff --git a/shell/common/platform_view.cc b/shell/common/platform_view.cc
index dc04f6302717f..69c404bffb261 100644
--- a/shell/common/platform_view.cc
+++ b/shell/common/platform_view.cc
@@ -33,39 +33,38 @@ std::unique_ptr<VsyncWaiter> PlatformView::CreateVSyncWaiter() {
 
 void PlatformView::DispatchPlatformMessage(
     fml::RefPtr<blink::PlatformMessage> message) {
-  delegate_.OnPlatformViewDispatchPlatformMessage(*this, std::move(message));
+  delegate_.OnPlatformViewDispatchPlatformMessage(std::move(message));
 }
 
 void PlatformView::DispatchPointerDataPacket(
     std::unique_ptr<blink::PointerDataPacket> packet) {
-  delegate_.OnPlatformViewDispatchPointerDataPacket(*this, std::move(packet));
+  delegate_.OnPlatformViewDispatchPointerDataPacket(std::move(packet));
 }
 
 void PlatformView::DispatchSemanticsAction(int32_t id,
                                            blink::SemanticsAction action,
                                            std::vector<uint8_t> args) {
-  delegate_.OnPlatformViewDispatchSemanticsAction(*this, id, action,
-                                                  std::move(args));
+  delegate_.OnPlatformViewDispatchSemanticsAction(id, action, std::move(args));
 }
 
 void PlatformView::SetSemanticsEnabled(bool enabled) {
-  delegate_.OnPlatformViewSetSemanticsEnabled(*this, enabled);
+  delegate_.OnPlatformViewSetSemanticsEnabled(enabled);
 }
 
 void PlatformView::SetAccessibilityFeatures(int32_t flags) {
-  delegate_.OnPlatformViewSetAccessibilityFeatures(*this, flags);
+  delegate_.OnPlatformViewSetAccessibilityFeatures(flags);
 }
 
 void PlatformView::SetViewportMetrics(const blink::ViewportMetrics& metrics) {
-  delegate_.OnPlatformViewSetViewportMetrics(*this, metrics);
+  delegate_.OnPlatformViewSetViewportMetrics(metrics);
 }
 
 void PlatformView::NotifyCreated() {
-  delegate_.OnPlatformViewCreated(*this, CreateRenderingSurface());
+  delegate_.OnPlatformViewCreated(CreateRenderingSurface());
 }
 
 void PlatformView::NotifyDestroyed() {
-  delegate_.OnPlatformViewDestroyed(*this);
+  delegate_.OnPlatformViewDestroyed();
 }
 
 sk_sp<GrContext> PlatformView::CreateResourceContext() const {
@@ -91,15 +90,15 @@ void PlatformView::HandlePlatformMessage(
 void PlatformView::OnPreEngineRestart() const {}
 
 void PlatformView::RegisterTexture(std::shared_ptr<flow::Texture> texture) {
-  delegate_.OnPlatformViewRegisterTexture(*this, std::move(texture));
+  delegate_.OnPlatformViewRegisterTexture(std::move(texture));
 }
 
 void PlatformView::UnregisterTexture(int64_t texture_id) {
-  delegate_.OnPlatformViewUnregisterTexture(*this, texture_id);
+  delegate_.OnPlatformViewUnregisterTexture(texture_id);
 }
 
 void PlatformView::MarkTextureFrameAvailable(int64_t texture_id) {
-  delegate_.OnPlatformViewMarkTextureFrameAvailable(*this, texture_id);
+  delegate_.OnPlatformViewMarkTextureFrameAvailable(texture_id);
 }
 
 std::unique_ptr<Surface> PlatformView::CreateRenderingSurface() {
@@ -115,7 +114,7 @@ void PlatformView::SetNextFrameCallback(fml::closure closure) {
     return;
   }
 
-  delegate_.OnPlatformViewSetNextFrameCallback(*this, std::move(closure));
+  delegate_.OnPlatformViewSetNextFrameCallback(std::move(closure));
 }
 
 }  // namespace shell
diff --git a/shell/common/platform_view.h b/shell/common/platform_view.h
index 0d09a7c1657e7..b727ad7179006 100644
--- a/shell/common/platform_view.h
+++ b/shell/common/platform_view.h
@@ -29,48 +29,36 @@ class PlatformView {
  public:
   class Delegate {
    public:
-    virtual void OnPlatformViewCreated(const PlatformView& view,
-                                       std::unique_ptr<Surface> surface) = 0;
+    virtual void OnPlatformViewCreated(std::unique_ptr<Surface> surface) = 0;
 
-    virtual void OnPlatformViewDestroyed(const PlatformView& view) = 0;
+    virtual void OnPlatformViewDestroyed() = 0;
 
-    virtual void OnPlatformViewSetNextFrameCallback(const PlatformView& view,
-                                                    fml::closure closure) = 0;
+    virtual void OnPlatformViewSetNextFrameCallback(fml::closure closure) = 0;
 
     virtual void OnPlatformViewSetViewportMetrics(
-        const PlatformView& view,
         const blink::ViewportMetrics& metrics) = 0;
 
     virtual void OnPlatformViewDispatchPlatformMessage(
-        const PlatformView& view,
         fml::RefPtr<blink::PlatformMessage> message) = 0;
 
     virtual void OnPlatformViewDispatchPointerDataPacket(
-        const PlatformView& view,
         std::unique_ptr<blink::PointerDataPacket> packet) = 0;
 
     virtual void OnPlatformViewDispatchSemanticsAction(
-        const PlatformView& view,
         int32_t id,
         blink::SemanticsAction action,
         std::vector<uint8_t> args) = 0;
 
-    virtual void OnPlatformViewSetSemanticsEnabled(const PlatformView& view,
-                                                   bool enabled) = 0;
+    virtual void OnPlatformViewSetSemanticsEnabled(bool enabled) = 0;
 
-    virtual void OnPlatformViewSetAccessibilityFeatures(
-        const PlatformView& view,
-        int32_t flags) = 0;
+    virtual void OnPlatformViewSetAccessibilityFeatures(int32_t flags) = 0;
 
     virtual void OnPlatformViewRegisterTexture(
-        const PlatformView& view,
         std::shared_ptr<flow::Texture> texture) = 0;
 
-    virtual void OnPlatformViewUnregisterTexture(const PlatformView& view,
-                                                 int64_t texture_id) = 0;
+    virtual void OnPlatformViewUnregisterTexture(int64_t texture_id) = 0;
 
     virtual void OnPlatformViewMarkTextureFrameAvailable(
-        const PlatformView& view,
         int64_t texture_id) = 0;
   };
 
diff --git a/shell/common/shell.cc b/shell/common/shell.cc
index 47bb2fac5991d..fb6df3f6958bb 100644
--- a/shell/common/shell.cc
+++ b/shell/common/shell.cc
@@ -393,10 +393,8 @@ blink::DartVM& Shell::GetDartVM() const {
 }
 
 // |shell::PlatformView::Delegate|
-void Shell::OnPlatformViewCreated(const PlatformView& view,
-                                  std::unique_ptr<Surface> surface) {
+void Shell::OnPlatformViewCreated(std::unique_ptr<Surface> surface) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   // Note:
@@ -435,9 +433,8 @@ void Shell::OnPlatformViewCreated(const PlatformView& view,
 }
 
 // |shell::PlatformView::Delegate|
-void Shell::OnPlatformViewDestroyed(const PlatformView& view) {
+void Shell::OnPlatformViewDestroyed() {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   // Note:
@@ -485,10 +482,8 @@ void Shell::OnPlatformViewDestroyed(const PlatformView& view) {
 
 // |shell::PlatformView::Delegate|
 void Shell::OnPlatformViewSetViewportMetrics(
-    const PlatformView& view,
     const blink::ViewportMetrics& metrics) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   task_runners_.GetUITaskRunner()->PostTask(
@@ -501,10 +496,8 @@ void Shell::OnPlatformViewSetViewportMetrics(
 
 // |shell::PlatformView::Delegate|
 void Shell::OnPlatformViewDispatchPlatformMessage(
-    const PlatformView& view,
     fml::RefPtr<blink::PlatformMessage> message) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   task_runners_.GetUITaskRunner()->PostTask(
@@ -517,10 +510,8 @@ void Shell::OnPlatformViewDispatchPlatformMessage(
 
 // |shell::PlatformView::Delegate|
 void Shell::OnPlatformViewDispatchPointerDataPacket(
-    const PlatformView& view,
     std::unique_ptr<blink::PointerDataPacket> packet) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
   task_runners_.GetUITaskRunner()->PostTask(fml::MakeCopyable(
       [engine = engine_->GetWeakPtr(), packet = std::move(packet)] {
@@ -531,12 +522,10 @@ void Shell::OnPlatformViewDispatchPointerDataPacket(
 }
 
 // |shell::PlatformView::Delegate|
-void Shell::OnPlatformViewDispatchSemanticsAction(const PlatformView& view,
-                                                  int32_t id,
+void Shell::OnPlatformViewDispatchSemanticsAction(int32_t id,
                                                   blink::SemanticsAction action,
                                                   std::vector<uint8_t> args) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   task_runners_.GetUITaskRunner()->PostTask(
@@ -548,10 +537,8 @@ void Shell::OnPlatformViewDispatchSemanticsAction(const PlatformView& view,
 }
 
 // |shell::PlatformView::Delegate|
-void Shell::OnPlatformViewSetSemanticsEnabled(const PlatformView& view,
-                                              bool enabled) {
+void Shell::OnPlatformViewSetSemanticsEnabled(bool enabled) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   task_runners_.GetUITaskRunner()->PostTask(
@@ -563,10 +550,8 @@ void Shell::OnPlatformViewSetSemanticsEnabled(const PlatformView& view,
 }
 
 // |shell::PlatformView::Delegate|
-void Shell::OnPlatformViewSetAccessibilityFeatures(const PlatformView& view,
-                                                   int32_t flags) {
+void Shell::OnPlatformViewSetAccessibilityFeatures(int32_t flags) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   task_runners_.GetUITaskRunner()->PostTask(
@@ -579,10 +564,8 @@ void Shell::OnPlatformViewSetAccessibilityFeatures(const PlatformView& view,
 
 // |shell::PlatformView::Delegate|
 void Shell::OnPlatformViewRegisterTexture(
-    const PlatformView& view,
     std::shared_ptr<flow::Texture> texture) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   task_runners_.GetGPUTaskRunner()->PostTask(
@@ -596,10 +579,8 @@ void Shell::OnPlatformViewRegisterTexture(
 }
 
 // |shell::PlatformView::Delegate|
-void Shell::OnPlatformViewUnregisterTexture(const PlatformView& view,
-                                            int64_t texture_id) {
+void Shell::OnPlatformViewUnregisterTexture(int64_t texture_id) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   task_runners_.GetGPUTaskRunner()->PostTask(
@@ -613,10 +594,8 @@ void Shell::OnPlatformViewUnregisterTexture(const PlatformView& view,
 }
 
 // |shell::PlatformView::Delegate|
-void Shell::OnPlatformViewMarkTextureFrameAvailable(const PlatformView& view,
-                                                    int64_t texture_id) {
+void Shell::OnPlatformViewMarkTextureFrameAvailable(int64_t texture_id) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   // Tell the rasterizer that one of its textures has a new frame available.
@@ -646,10 +625,8 @@ void Shell::OnPlatformViewMarkTextureFrameAvailable(const PlatformView& view,
 }
 
 // |shell::PlatformView::Delegate|
-void Shell::OnPlatformViewSetNextFrameCallback(const PlatformView& view,
-                                               fml::closure closure) {
+void Shell::OnPlatformViewSetNextFrameCallback(fml::closure closure) {
   FML_DCHECK(is_setup_);
-  FML_DCHECK(&view == platform_view_.get());
   FML_DCHECK(task_runners_.GetPlatformTaskRunner()->RunsTasksOnCurrentThread());
 
   task_runners_.GetGPUTaskRunner()->PostTask(
@@ -661,8 +638,7 @@ void Shell::OnPlatformViewSetNextFrameCallback(const PlatformView& view,
 }
 
 // |shell::Animator::Delegate|
-void Shell::OnAnimatorBeginFrame(const Animator& animator,
-                                 fml::TimePoint frame_time) {
+void Shell::OnAnimatorBeginFrame(fml::TimePoint frame_time) {
   FML_DCHECK(is_setup_);
   FML_DCHECK(task_runners_.GetUITaskRunner()->RunsTasksOnCurrentThread());
 
@@ -672,7 +648,7 @@ void Shell::OnAnimatorBeginFrame(const Animator& animator,
 }
 
 // |shell::Animator::Delegate|
-void Shell::OnAnimatorNotifyIdle(const Animator& animator, int64_t deadline) {
+void Shell::OnAnimatorNotifyIdle(int64_t deadline) {
   FML_DCHECK(is_setup_);
   FML_DCHECK(task_runners_.GetUITaskRunner()->RunsTasksOnCurrentThread());
 
@@ -683,7 +659,6 @@ void Shell::OnAnimatorNotifyIdle(const Animator& animator, int64_t deadline) {
 
 // |shell::Animator::Delegate|
 void Shell::OnAnimatorDraw(
-    const Animator& animator,
     fml::RefPtr<flutter::Pipeline<flow::LayerTree>> pipeline) {
   FML_DCHECK(is_setup_);
 
@@ -697,7 +672,7 @@ void Shell::OnAnimatorDraw(
 }
 
 // |shell::Animator::Delegate|
-void Shell::OnAnimatorDrawLastLayerTree(const Animator& animator) {
+void Shell::OnAnimatorDrawLastLayerTree() {
   FML_DCHECK(is_setup_);
 
   task_runners_.GetGPUTaskRunner()->PostTask(
@@ -710,7 +685,6 @@ void Shell::OnAnimatorDrawLastLayerTree(const Animator& animator) {
 
 // |shell::Engine::Delegate|
 void Shell::OnEngineUpdateSemantics(
-    const Engine& engine,
     blink::SemanticsNodeUpdates update,
     blink::CustomAccessibilityActionUpdates actions) {
   FML_DCHECK(is_setup_);
@@ -727,7 +701,6 @@ void Shell::OnEngineUpdateSemantics(
 
 // |shell::Engine::Delegate|
 void Shell::OnEngineHandlePlatformMessage(
-    const Engine& engine,
     fml::RefPtr<blink::PlatformMessage> message) {
   FML_DCHECK(is_setup_);
   FML_DCHECK(task_runners_.GetUITaskRunner()->RunsTasksOnCurrentThread());
diff --git a/shell/common/shell.h b/shell/common/shell.h
index 41798664cda63..62723fde78521 100644
--- a/shell/common/shell.h
+++ b/shell/common/shell.h
@@ -115,84 +115,68 @@ class Shell final : public PlatformView::Delegate,
              std::unique_ptr<IOManager> io_manager);
 
   // |shell::PlatformView::Delegate|
-  void OnPlatformViewCreated(const PlatformView& view,
-                             std::unique_ptr<Surface> surface) override;
+  void OnPlatformViewCreated(std::unique_ptr<Surface> surface) override;
 
   // |shell::PlatformView::Delegate|
-  void OnPlatformViewDestroyed(const PlatformView& view) override;
+  void OnPlatformViewDestroyed() override;
 
   // |shell::PlatformView::Delegate|
   void OnPlatformViewSetViewportMetrics(
-      const PlatformView& view,
       const blink::ViewportMetrics& metrics) override;
 
   // |shell::PlatformView::Delegate|
   void OnPlatformViewDispatchPlatformMessage(
-      const PlatformView& view,
       fml::RefPtr<blink::PlatformMessage> message) override;
 
   // |shell::PlatformView::Delegate|
   void OnPlatformViewDispatchPointerDataPacket(
-      const PlatformView& view,
       std::unique_ptr<blink::PointerDataPacket> packet) override;
 
   // |shell::PlatformView::Delegate|
   void OnPlatformViewDispatchSemanticsAction(
-      const PlatformView& view,
       int32_t id,
       blink::SemanticsAction action,
       std::vector<uint8_t> args) override;
 
   // |shell::PlatformView::Delegate|
-  void OnPlatformViewSetSemanticsEnabled(const PlatformView& view,
-                                         bool enabled) override;
+  void OnPlatformViewSetSemanticsEnabled(bool enabled) override;
 
   // |shell:PlatformView::Delegate|
-  void OnPlatformViewSetAccessibilityFeatures(const PlatformView& view,
-                                              int32_t flags) override;
+  void OnPlatformViewSetAccessibilityFeatures(int32_t flags) override;
 
   // |shell::PlatformView::Delegate|
   void OnPlatformViewRegisterTexture(
-      const PlatformView& view,
       std::shared_ptr<flow::Texture> texture) override;
 
   // |shell::PlatformView::Delegate|
-  void OnPlatformViewUnregisterTexture(const PlatformView& view,
-                                       int64_t texture_id) override;
+  void OnPlatformViewUnregisterTexture(int64_t texture_id) override;
 
   // |shell::PlatformView::Delegate|
-  void OnPlatformViewMarkTextureFrameAvailable(const PlatformView& view,
-                                               int64_t texture_id) override;
+  void OnPlatformViewMarkTextureFrameAvailable(int64_t texture_id) override;
 
   // |shell::PlatformView::Delegate|
-  void OnPlatformViewSetNextFrameCallback(const PlatformView& view,
-                                          fml::closure closure) override;
+  void OnPlatformViewSetNextFrameCallback(fml::closure closure) override;
 
   // |shell::Animator::Delegate|
-  void OnAnimatorBeginFrame(const Animator& animator,
-                            fml::TimePoint frame_time) override;
+  void OnAnimatorBeginFrame(fml::TimePoint frame_time) override;
 
   // |shell::Animator::Delegate|
-  void OnAnimatorNotifyIdle(const Animator& animator,
-                            int64_t deadline) override;
+  void OnAnimatorNotifyIdle(int64_t deadline) override;
 
   // |shell::Animator::Delegate|
   void OnAnimatorDraw(
-      const Animator& animator,
       fml::RefPtr<flutter::Pipeline<flow::LayerTree>> pipeline) override;
 
   // |shell::Animator::Delegate|
-  void OnAnimatorDrawLastLayerTree(const Animator& animator) override;
+  void OnAnimatorDrawLastLayerTree() override;
 
   // |shell::Engine::Delegate|
   void OnEngineUpdateSemantics(
-      const Engine& engine,
       blink::SemanticsNodeUpdates update,
       blink::CustomAccessibilityActionUpdates actions) override;
 
   // |shell::Engine::Delegate|
   void OnEngineHandlePlatformMessage(
-      const Engine& engine,
       fml::RefPtr<blink::PlatformMessage> message) override;
 
   // |shell::Engine::Delegate|