Fix latest_frame_target_time race

shell/common/animator.cc

@@ -190,7 +190,7 @@ void Animator::Render(std::unique_ptr<flutter::LayerTree> layer_tree) {
     FML_DLOG(INFO) << "No pending continuation to commit";
   }
 
-  delegate_.OnAnimatorDraw(layer_tree_pipeline_);
+  delegate_.OnAnimatorDraw(layer_tree_pipeline_, last_frame_target_time_);
 }
 
 bool Animator::CanReuseLastLayerTree() {

shell/common/animator.h

@@ -35,7 +35,8 @@ class Animator final {
     virtual void OnAnimatorNotifyIdle(int64_t deadline) = 0;
 
     virtual void OnAnimatorDraw(
-        fml::RefPtr<Pipeline<flutter::LayerTree>> pipeline) = 0;
+        fml::RefPtr<Pipeline<flutter::LayerTree>> pipeline,
+        fml::TimePoint frame_target_time) = 0;
 
     virtual void OnAnimatorDrawLastLayerTree() = 0;
   };

shell/common/shell.cc

@@ -952,9 +952,20 @@ void Shell::OnAnimatorNotifyIdle(int64_t deadline) {
 }
 
 // |Animator::Delegate|
-void Shell::OnAnimatorDraw(fml::RefPtr<Pipeline<flutter::LayerTree>> pipeline) {
+void Shell::OnAnimatorDraw(fml::RefPtr<Pipeline<flutter::LayerTree>> pipeline,
+                           fml::TimePoint frame_target_time) {
   FML_DCHECK(is_setup_);
 
+  // record the target time for use by rasterizer.
+  {
+    std::scoped_lock time_recorder_lock(time_recorder_mutex_);
+    if (!latest_frame_target_time_) {
+      latest_frame_target_time_ = frame_target_time;
+    } else if (latest_frame_target_time_ < frame_target_time) {
+      latest_frame_target_time_ = frame_target_time;
+    }
+  }
+
   task_runners_.GetRasterTaskRunner()->PostTask(
       [&waiting_for_first_frame = waiting_for_first_frame_,
        &waiting_for_first_frame_condition = waiting_for_first_frame_condition_,

shell/common/shell.h

@@ -489,8 +489,8 @@ class Shell final : public PlatformView::Delegate,
   void OnAnimatorNotifyIdle(int64_t deadline) override;
 
   // |Animator::Delegate|
-  void OnAnimatorDraw(
-      fml::RefPtr<Pipeline<flutter::LayerTree>> pipeline) override;
+  void OnAnimatorDraw(fml::RefPtr<Pipeline<flutter::LayerTree>> pipeline,
+                      fml::TimePoint frame_target_time) override;
 
   // |Animator::Delegate|
   void OnAnimatorDrawLastLayerTree() override;