Convert to async/await parts that cause strong mode warnings.

pkg/analysis_server/tool/spec/codegen_inttest_methods.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.
 
 /**
  * Code generation for the file "integration_test_methods.dart".
  */
 library codegenInttestMethods;
 
 import 'dart:convert';
@@ skipping 207 matching lines @@
     }));
     String resultClass;
     String futureClass;
     if (request.result == null) {
       futureClass = 'Future';
     } else {
       resultClass = camelJoin([request.domainName, request.method, 'result'],
           doCapitalize: true);
       futureClass = 'Future<$resultClass>';
     }
-    writeln('$futureClass $methodName(${args.join(', ')}) {');
+    writeln('$futureClass $methodName(${args.join(', ')}) async {');
     indent(() {
       String requestClass = camelJoin(
           [request.domainName, request.method, 'params'],
           doCapitalize: true);
       String paramsVar = 'null';
       if (request.params != null) {
         paramsVar = 'params';
         List<String> args = <String>[];
         List<String> optionalArgs = <String>[];
         for (TypeObjectField field in request.params.fields) {
           if (field.optional) {
             optionalArgs.add('${field.name}: ${field.name}');
           } else {
             args.add(field.name);
           }
         }
         args.addAll(optionalArgs);
         writeln('var params = new $requestClass(${args.join(', ')}).toJson();');
       }
-      writeln(
-          'return server.send(${JSON.encode(request.longMethod)}, $paramsVar)');
-      indent(() {
-        writeln('  .then((result) {');
-        if (request.result != null) {
-          String kind = 'null';
-          if (requestClass == 'EditGetRefactoringParams') {
-            kind = 'kind';
-          }
-          writeln('ResponseDecoder decoder = new ResponseDecoder($kind);');
-          writeln(
-              "return new $resultClass.fromJson(decoder, 'result', result);");
-        } else {
-          writeln('expect(result, isNull);');
-          writeln('return null;');
+      String methodJson = JSON.encode(request.longMethod);
+      writeln('var result = await server.send($methodJson, $paramsVar);');
+      if (request.result != null) {
+        String kind = 'null';
+        if (requestClass == 'EditGetRefactoringParams') {
+          kind = 'kind';
         }
-      });
-      writeln('});');
+        writeln('ResponseDecoder decoder = new ResponseDecoder($kind);');
+        writeln("return new $resultClass.fromJson(decoder, 'result', result);");
+      } else {
+        writeln('expect(result, isNull);');
+        writeln('return null;');
+      }
     });
     writeln('}');
   }
 }