Add a diagnostic.getServerPort analysis server request.

pkg/analysis_server/tool/spec/generated/java/types/RequestErrorCode.java

 /*
  * Copyright (c) 2015, the Dart project authors.
  *
  * Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
  *
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Unless required by applicable law or agreed to in writing, software distributed under the License
  * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
@@ skipping 12 matching lines @@
  */
 public class RequestErrorCode {
 
   /**
    * An "analysis.getErrors" or "analysis.getNavigation" request could not be satisfied because the
    * content of the file changed before the requested results could be computed.
    */
   public static final String CONTENT_MODIFIED = "CONTENT_MODIFIED";
 
   /**
+   * The server was unable to open a port for the diagnostic server.
+   */
+  public static final String DEBUG_PORT_COULD_NOT_BE_OPENED = "DEBUG_PORT_COULD_NOT_BE_OPENED";
+
+  /**
    * A request specified a FilePath which does not match a file in an analysis root, or the requested
    * operation is not available for the file.
    */
   public static final String FILE_NOT_ANALYZED = "FILE_NOT_ANALYZED";
 
   /**
    * An "edit.format" request specified a FilePath which does not match a Dart file in an analysis
    * root.
    */
   public static final String FORMAT_INVALID_FILE = "FORMAT_INVALID_FILE";
@@ skipping 113 matching lines @@
   public static final String UNKNOWN_SOURCE = "UNKNOWN_SOURCE";
 
   /**
    * The analysis server was requested to perform an action which is not supported.
    *
    * This is a legacy error; it will be removed before the API reaches version 1.0.
    */
   public static final String UNSUPPORTED_FEATURE = "UNSUPPORTED_FEATURE";
 
 }