Issue 28068. Implement diagnostics domain for the new analysis driver.

pkg/analyzer/lib/src/dart/analysis/driver.dart

 // Copyright (c) 2016, 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.
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:typed_data';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart' show CompilationUnitElement;
@@ skipping 279 matching lines @@
   }
 
   /**
    * Return the set of files that are known at this moment. This set does not
    * always include all added files or all implicitly used file. If a file has
    * not been processed yet, it might be missing.
    */
   Set<String> get knownFiles => _fsState.knownFilePaths;
 
   /**
+   * Return the number of files scheduled for analysis.
+   */
+  int get numberOfFilesToAnalyze => _filesToAnalyze.length;
+
+  /**
    * Return the list of files that the driver should try to analyze sooner.
    */
   List<String> get priorityFiles => _priorityFiles.toList(growable: false);
 
   /**
    * Set the list of files that the driver should try to analyze sooner.
    *
    * Every path in the list must be absolute and normalized.
    *
    * The driver will produce the results through the [results] stream. The
@@ skipping 1365 matching lines @@
           libraryDeclarations.add(new TopLevelDeclarationInSource(
               file.source, declaration, isExported));
         }
       }
     }
 
     // We're not done yet.
     return false;
   }
 }