Use faster way to get AnalysisContext in execution domain notifications.

pkg/analysis_server/lib/src/domain_execution.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.execution;
 
 import 'dart:async';
 import 'dart:collection';
 
 import 'package:analysis_server/src/analysis_server.dart';
@@ skipping 136 matching lines @@
         onFileAnalyzed = null;
       }
     }
     return new ExecutionSetSubscriptionsResult().toResponse(request.id);
   }
 
   void _fileAnalyzed(ChangeNotice notice) {
     ServerPerformanceStatistics.executionNotifications.makeCurrentWhile(() {
       Source source = notice.source;
       String filePath = source.fullName;
-      if (!_isInAnalysisRoot(filePath)) {
-        return;
-      }
-      AnalysisContext context = server.getAnalysisContext(filePath);
+      AnalysisContext context = server.getContainingContext(filePath);
       if (context == null) {
         return;
       }
       if (AnalysisEngine.isDartFileName(filePath)) {
         ExecutableKind kind = ExecutableKind.NOT_EXECUTABLE;
         if (context.isClientLibrary(source)) {
           kind = ExecutableKind.CLIENT;
           if (context.isServerLibrary(source)) {
             kind = ExecutableKind.EITHER;
           }
@@ skipping 58 matching lines @@
     if (_isInAnalysisRoot(filePath)) {
       server.sendNotification(
           new ExecutionLaunchDataParams(filePath, kind: kind).toNotification());
     }
   }
 
   static List<String> _getFullNames(List<Source> sources) {
     return sources.map((Source source) => source.fullName).toList();
   }
 }