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runtime/observatory/lib/src/elements/debugger.dart

Index: runtime/observatory/lib/src/elements/debugger.dart
diff --git a/runtime/observatory/lib/src/elements/debugger.dart b/runtime/observatory/lib/src/elements/debugger.dart
index 9b3bced72e51a0178c6b80ecffa784f9ee00a74c..863928bdf63d872efeca9fe029b99101bfb75a15 100644
--- a/runtime/observatory/lib/src/elements/debugger.dart
+++ b/runtime/observatory/lib/src/elements/debugger.dart
@@ -1658,30 +1658,30 @@ class ObservatoryDebugger extends Debugger {
       var event = isolate.pauseEvent;
       if (event.kind == ServiceEvent.kPauseStart) {
         console.print("Type 'continue' [F7] or 'step' [F10] to start the isolate");
-        return;
+        return null;
       }
       if (event.kind == ServiceEvent.kPauseExit) {
         console.print("Type 'continue' [F7] to exit the isolate");
-        return;
+        return null;
       }
       return isolate.stepOver();
     } else {
       console.print('The program is already running');
-      return;
+      return null;
     }
   }
 
-  Future step() {
+  Future step() async {
     if (isolatePaused()) {
       var event = isolate.pauseEvent;
       if (event.kind == ServiceEvent.kPauseExit) {
         console.print("Type 'continue' [F7] to exit the isolate");
-        return new Future.value(null);
+        return null;
       }
       return isolate.stepInto();
     } else {
       console.print('The program is already running');
-      return new Future.value(null);
+      return null;
     }
   }
 }
@@ -1784,7 +1784,7 @@ class DebuggerPageElement extends ObservatoryElement {
   void detached() {
     debugger.isolate = null;
     _resizeSubscription.cancel();
-    _resizeSubscrption = null;
+    _resizeSubscription = null;
     cancelFutureSubscription(_isolateSubscriptionFuture);
     _isolateSubscriptionFuture = null;
     cancelFutureSubscription(_debugSubscriptionFuture);