Add '--useAnalysisHighlight2' option to generate version 2 of semantic highlight.

pkg/analysis_server/lib/src/operation/operation_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 operation.analysis;
 
 import 'package:analysis_server/src/analysis_server.dart';
 import 'package:analysis_server/src/computer/computer_highlights.dart';
+import 'package:analysis_server/src/computer/computer_highlights2.dart';
 import 'package:analysis_server/src/computer/computer_navigation.dart';
 import 'package:analysis_server/src/computer/computer_occurrences.dart';
 import 'package:analysis_server/src/computer/computer_outline.dart';
 import 'package:analysis_server/src/computer/computer_overrides.dart';
 import 'package:analysis_server/src/operation/operation.dart';
 import 'package:analysis_server/src/protocol_server.dart' as protocol;
 import 'package:analysis_server/src/services/dependencies/library_dependencies.dart';
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analyzer/src/generated/ast.dart';
 import 'package:analyzer/src/generated/engine.dart';
@@ skipping 123 matching lines @@
     if (files != null && files.isNotEmpty) {
       var params = new protocol.AnalysisFlushResultsParams(files);
       server.sendNotification(params.toNotification());
     }
   });
 }
 
 void sendAnalysisNotificationHighlights(
     AnalysisServer server, String file, CompilationUnit dartUnit) {
   _sendNotification(server, () {
-    var regions = new DartUnitHighlightsComputer(dartUnit).compute();
+    List<protocol.HighlightRegion> regions;
+    if (server.options.useAnalysisHighlight2) {
+      regions = new DartUnitHighlightsComputer2(dartUnit).compute();
+    } else {
+      regions = new DartUnitHighlightsComputer(dartUnit).compute();
+    }
     var params = new protocol.AnalysisHighlightsParams(file, regions);
     server.sendNotification(params.toNotification());
   });
 }
 
 void sendAnalysisNotificationNavigation(
     AnalysisServer server, String file, CompilationUnit dartUnit) {
   _sendNotification(server, () {
     var computer = new DartUnitNavigationComputer();
     computer.compute(dartUnit);
@@ skipping 303 matching lines @@
 abstract class _SingleFileOperation extends SourceSensitiveOperation {
   final String file;
 
   _SingleFileOperation(AnalysisContext context, this.file) : super(context);
 
   @override
   bool shouldBeDiscardedOnSourceChange(Source source) {
     return source.fullName == file;
   }
 }