Remove ability to disable new analysis driver

pkg/analysis_server/lib/src/domain_diagnostic.dart

 // Copyright (c) 2015, 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:core';
 
 import 'package:analysis_server/protocol/protocol.dart';
 import 'package:analysis_server/protocol/protocol_generated.dart';
@@ skipping 19 matching lines @@
 class DiagnosticDomainHandler implements RequestHandler {
   /// The analysis server that is using this handler to process requests.
   final AnalysisServer server;
 
   /// Initialize a newly created handler to handle requests for the given
   /// [server].
   DiagnosticDomainHandler(this.server);
 
   /// Answer the `diagnostic.getDiagnostics` request.
   Response computeDiagnostics(Request request) {
-    List<ContextData> contexts = <ContextData>[];
-    if (server.options.enableNewAnalysisDriver) {
-      contexts = server.driverMap.values.map(extractDataFromDriver).toList();
-    } else {
-      for (AnalysisContext context in server.analysisContexts) {
-        contexts.add(extractDataFromContext(context));
-      }
-    }
+    List<ContextData> contexts =
+        server.driverMap.values.map(extractDataFromDriver).toList();
     return new DiagnosticGetDiagnosticsResult(contexts).toResponse(request.id);
   }
 
   /// Extract context data from the given [context].
   ContextData extractDataFromContext(AnalysisContext context) {
     int explicitFiles = 0;
     int implicitFiles = 0;
     int workItems = 0;
     Set<String> exceptions = new HashSet<String>();
     if (context is AnalysisContextImpl) {
@@ skipping 67 matching lines @@
   }
 }
 
 class MemoryCpuSample {
   final DateTime time;
   final double cpuPercentage;
   final int memoryKB;
 
   MemoryCpuSample(this.time, this.cpuPercentage, this.memoryKB);
 }