Fix reload_sources_test flake

runtime/observatory/lib/event.dart

Index: runtime/observatory/lib/event.dart
diff --git a/runtime/observatory/lib/event.dart b/runtime/observatory/lib/event.dart
index 50401fd229628ce270ac2a33a24589d3d8f6442c..07c7d4156338e79616c12568664674e3c2b1a08f 100644
--- a/runtime/observatory/lib/event.dart
+++ b/runtime/observatory/lib/event.dart
@@ -139,7 +139,7 @@ class PauseInterruptedEvent implements M.PauseInterruptedEvent {
 }
 
 
-class PausePostRequestEvent implements M.PauseInterruptedEvent {
+class PausePostRequestEvent implements M.PausePostRequestEvent {
   final DateTime timestamp;
   final M.IsolateRef isolate;
   final M.Frame topFrame;