Send responses for any pending 'analysis.getErrors' requests during context removal.

pkg/analysis_server/lib/src/domain_analysis.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library domain.analysis;
 
 import 'dart:collection';
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/computer/computer_hover.dart';
@@ skipping 29 matching lines @@
       Response response = new Response(request.id);
       AnalysisErrorInfo errorInfo = server.getErrors(file);
       if (errorInfo == null) {
         response.setResult(ERRORS, []);
       } else {
         response.setResult(ERRORS, errorInfo.errors.map((AnalysisError error) {
           return errorToJson(errorInfo.lineInfo, error);
         }).toList());
       }
       server.sendResponse(response);
+    }).catchError((message) {
+      if (message is! String) {
+        AnalysisEngine.instance.logger.logError(
+            'Illegal error message during getErrors: $message');
+        message = '';
+      }
+      Response response = new Response.getErrorsError(request, message);
+      response.setResult(ERRORS, []);
+      server.sendResponse(response);
     });
     // delay response
     return Response.DELAYED_RESPONSE;
   }
 
   /**
    * Implement the `analysis.getHover` request.
    */
   Response getHover(Request request) {
     // prepare parameters
@@ skipping 189 matching lines @@
 
 /**
  * A description of the change to the content of a file.
  */
 class ContentChange {
   String content;
   int offset;
   int oldLength;
   int newLength;
 }