close channel and exit analysis server on editor shutdown

editor/tools/plugins/com.google.dart.server_test/src/com/google/dart/server/internal/remote/TestRequestSink.java

Index: editor/tools/plugins/com.google.dart.server_test/src/com/google/dart/server/internal/remote/TestRequestSink.java
diff --git a/editor/tools/plugins/com.google.dart.server_test/src/com/google/dart/server/internal/remote/TestRequestSink.java b/editor/tools/plugins/com.google.dart.server_test/src/com/google/dart/server/internal/remote/TestRequestSink.java
index 4ceb44973417e46c7be90db344aa28e966412556..735c7c850984277914b932d39a1edb2dad3676ed 100644
--- a/editor/tools/plugins/com.google.dart.server_test/src/com/google/dart/server/internal/remote/TestRequestSink.java
+++ b/editor/tools/plugins/com.google.dart.server_test/src/com/google/dart/server/internal/remote/TestRequestSink.java
@@ -24,16 +24,26 @@ import java.util.List;
  */
 public class TestRequestSink implements RequestSink {
   private final List<JsonObject> requests = Lists.newArrayList();
+  private boolean isClosed = false;
 
   @Override
   public void add(JsonObject request) {
     requests.add(request);
   }
 
+  @Override
+  public void close() {
+    isClosed = true;
+  }
+
   /**
    * Returns recorded requests.
    */
   public List<JsonObject> getRequests() {
     return requests;
   }
+
+  public boolean isClosed() {
+    return isClosed;
+  }
 }