Remove unused fields from analysis_server.

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 b6ea93ee806928093f9a9ecdda72e016565fac42..65ca8bab1826edab35e5cd84e0c95446f4c043a0 100644
--- a/pkg/analysis_server/test/integration/integration_tests.dart
+++ b/pkg/analysis_server/test/integration/integration_tests.dart
@@ -643,11 +643,6 @@ class Server {
   int _nextId = 0;
 
   /**
-   * [StreamController] to which notifications will be sent.
-   */
-  final StreamController _notifications = new StreamController();
-
-  /**
    * Messages which have been exchanged with the server; we buffer these
    * up until the test finishes, so that they can be examined in the debugger
    * or printed out in response to a call to [debugStdio].