Add additional Schedule heartbeat calls.

sdk/lib/_internal/pub/test/test_pub.dart

Index: sdk/lib/_internal/pub/test/test_pub.dart
diff --git a/sdk/lib/_internal/pub/test/test_pub.dart b/sdk/lib/_internal/pub/test/test_pub.dart
index 6ac747b88d97fa2ddb36e475cfec60c3fb86c8e0..8d417edd1ef6aa220a942e84840e56cbcb4c9c30 100644
--- a/sdk/lib/_internal/pub/test/test_pub.dart
+++ b/sdk/lib/_internal/pub/test/test_pub.dart
@@ -100,10 +100,10 @@ void serve([List<d.Descriptor> contents]) {
       return SafeHttpServer.bind("localhost", 0).then((server) {
         _server = server;
         server.listen((request) {
+          currentSchedule.heartbeat();
           var response = request.response;
           try {
             var path = request.uri.path.replaceFirst("/", "");
-            currentSchedule.addDebugInfo("[$path] got request");
 
             if (_requestedPaths == null) _requestedPaths = <String>[];
             _requestedPaths.add(path);
@@ -112,20 +112,17 @@ void serve([List<d.Descriptor> contents]) {
             var stream = baseDir.load(path);
 
             new ByteStream(stream).toBytes().then((data) {
-              currentSchedule.addDebugInfo("[$path] sending response:\n"
-                  "${new String.fromCharCodes(data)}");
+              currentSchedule.heartbeat();
               response.statusCode = 200;
               response.contentLength = data.length;
               response.add(data);
               response.close();
             }).catchError((e) {
-              currentSchedule.addDebugInfo("[$path] got load error: $e");
               response.statusCode = 404;
               response.contentLength = 0;
               response.close();
             });
           } catch (e) {
-            currentSchedule.addDebugInfo("[$path] got error: $e");
             currentSchedule.signalError(e);
             response.statusCode = 500;
             response.close();