Update start_ttfb_metrics, stop_ttfb_metrics, start_processing_metrics, and stop_processing_metrics to accept start_time/end_time keyword arguments matching the updated FrameProcessorMetrics signatures. Closes #3808
Update start_ttfb_metrics, stop_ttfb_metrics, start_processing_metrics, and stop_processing_metrics to accept start_time/end_time keyword arguments matching the updated FrameProcessorMetrics signatures. Closes #3808