Make more use of generated classes in analysis server.

pkg/analysis_server/tool/spec/codegen_dart_protocol.dart

Index: pkg/analysis_server/tool/spec/codegen_dart_protocol.dart
diff --git a/pkg/analysis_server/tool/spec/codegen_dart_protocol.dart b/pkg/analysis_server/tool/spec/codegen_dart_protocol.dart
index bf2cbb3878ca811c3be8266e5231fab577ee7112..471a1487e1f93a08b1b4445f505b239375de58f2 100644
--- a/pkg/analysis_server/tool/spec/codegen_dart_protocol.dart
+++ b/pkg/analysis_server/tool/spec/codegen_dart_protocol.dart
@@ -476,7 +476,7 @@ class CodegenProtocolVisitor extends HierarchicalApiVisitor with CodeGenerator {
       } else {
         return new ToJsonSnippet(dartType(type), (String value) {
           StringBuffer result = new StringBuffer();
-          result.write('_mapMap($value');
+          result.write('mapMap($value');
           if (!keyCode.isIdentity) {
             result.write(', keyCallback: ${keyCode.asClosure}');
           }