performance measurement improvements

pkg/analysis_server/test/integration/integration_tests.dart

Index: pkg/analysis_server/test/integration/integration_tests.dart
diff --git a/pkg/analysis_server/test/integration/integration_tests.dart b/pkg/analysis_server/test/integration/integration_tests.dart
index 3b7e13af389e84dbc584423085fbacebd435f0b1..5471bda56f754d569efd29104b3c1d769ea2d89a 100644
--- a/pkg/analysis_server/test/integration/integration_tests.dart
+++ b/pkg/analysis_server/test/integration/integration_tests.dart
@@ -584,7 +584,7 @@ class Server {
    * `true`, the server will be started with "--observe" and
    * "--pause-isolates-on-exit", allowing the observatory to be used.
    */
-  Future start({bool debugServer: false, bool profileServer: false}) {
+  Future start({bool debugServer: false, int diagnosticPort, bool profileServer: false}) {
     if (_process != null) {
       throw new Exception('Process already started');
     }
@@ -606,6 +606,10 @@ class Server {
     }
     arguments.add('--checked');
     arguments.add(serverPath);
+    if (diagnosticPort != null) {
+      arguments.add('--port');
+      arguments.add(diagnosticPort.toString());
+    }
     return Process.start(dartBinary, arguments).then((Process process) {
       _process = process;
       process.exitCode.then((int code) {