Remove unused constant (#9808)

packages/devtools_app/lib/src/service/service_registrations.dart

diff --git a/packages/devtools_app/lib/src/service/service_registrations.dart b/packages/devtools_app/lib/src/service/service_registrations.dart
index 108503a..2f6c0bc 100644
--- a/packages/devtools_app/lib/src/service/service_registrations.dart
+++ b/packages/devtools_app/lib/src/service/service_registrations.dart
@@ -54,8 +54,6 @@
 
 String get flutterEngineEstimateRasterCache => flutterEngineRasterCache;
 
-const renderFrameWithRasterStats = '_flutter.renderFrameWithRasterStats';
-
 /// Dwds listens to events for recording end-to-end analytics.
 const dwdsSendEvent = 'ext.dwds.sendEvent';