performance measurement mods:

pkg/analysis_server/benchmark/integration/operation.dart

Index: pkg/analysis_server/benchmark/integration/operation.dart
diff --git a/pkg/analysis_server/benchmark/integration/operation.dart b/pkg/analysis_server/benchmark/integration/operation.dart
index f9ee62a676aca7661bd3f05696a677dba58442f3..5816a9ed3e3ac7282524846d0fb17440dd5ab075 100644
--- a/pkg/analysis_server/benchmark/integration/operation.dart
+++ b/pkg/analysis_server/benchmark/integration/operation.dart
@@ -169,6 +169,7 @@ class ResponseOperation extends Operation {
           'expected error:${format(expectedError)}\n'
           'but received:${format(actualResult)}';
       driver.results.recordUnexpectedResults(requestJson['method']);
+      converter.logOverlayContent();
       if (expectedError == null) {
         converter.logger.log(Level.SEVERE, message);
       } else {
@@ -179,13 +180,9 @@ class ResponseOperation extends Operation {
 }
 
 class StartServerOperation extends Operation {
-  final int diagnosticPort;
-
-  StartServerOperation({this.diagnosticPort});
-
   @override
   Future perform(Driver driver) {
-    return driver.startServer(diagnosticPort: diagnosticPort);
+    return driver.startServer();
   }
 }