More strong mode changes to analysis_server

pkg/analysis_server/benchmark/integration/log_file_input_converter.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.
 
 library input.transformer.log_file;
 
 import 'dart:convert';
 
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:logging/logging.dart';
@@ skipping 14 matching lines @@
 class LogFileInputConverter extends CommonInputConverter {
   LogFileInputConverter(String tmpSrcDirPath, PathMap srcPathMap)
       : super(tmpSrcDirPath, srcPathMap);
 
   @override
   Operation convert(String line) {
     try {
       String timeStampString = _parseTimeStamp(line);
       String data = line.substring(timeStampString.length);
       if (data.startsWith(RECEIVED_FRAGMENT)) {
-        Map<String, dynamic> json = JSON.decode(data.substring(4));
+        Map<String, dynamic> json = asMap(JSON.decode(data.substring(4)));
         if (json.containsKey('event')) {
           return convertNotification(json);
         } else {
           return convertResponse(json);
         }
       } else if (data.startsWith(SENT_FRAGMENT)) {
-        Map<String, dynamic> json = JSON.decode(data.substring(4));
+        Map<String, dynamic> json = asMap(JSON.decode(data.substring(4)));
         if (json.containsKey('method')) {
           return convertRequest(json);
         }
         return null;
       }
       logger.log(Level.INFO, 'unknown input line: $line');
       return null;
     } catch (e, s) {
       throw new AnalysisException(
           'Failed to parse line\n  $line', new CaughtException(e, s));
@@ skipping 22 matching lines @@
     while (index < line.length) {
       int code = line.codeUnitAt(index);
       if (code < ZERO || NINE < code) {
         return line.substring(0, index);
       }
       ++index;
     }
     return line;
   }
 }