Deprecate all diagnostics methods that use strings.

pkg/front_end/lib/src/fasta/testing/environment_variable.dart

 // Copyright (c) 2016, 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 fasta.testing.environment_variable;
 
 import 'dart:async' show Future;
 
 import 'dart:io' show Directory, File, Platform;
 
-import '../errors.dart' show inputError;
+import '../deprecated_problems.dart' show deprecated_inputError;
 
 class EnvironmentVariable {
   final String name;
 
   final String what;
 
   const EnvironmentVariable(this.name, this.what);
 
   Future<String> get value async {
     String value = Platform.environment[name];
     if (value == null) return variableNotDefined();
     await validate(value);
     return value;
   }
 
   Future<Null> validate(String value) => new Future<Null>.value();
 
   variableNotDefined() {
-    inputError(
+    deprecated_inputError(
         null, null, "The environment variable '$name' isn't defined. $what");
   }
 }
 
 class EnvironmentVariableFile extends EnvironmentVariable {
   const EnvironmentVariableFile(String name, String what) : super(name, what);
 
   Future<Null> validate(String value) async {
     if (!await new File(value).exists()) notFound(value);
     return null;
   }
 
   notFound(String value) {
-    inputError(
+    deprecated_inputError(
         null,
         null,
         "The environment variable '$name' has the value "
         "'$value', that isn't a file. $what");
   }
 }
 
 class EnvironmentVariableDirectory extends EnvironmentVariable {
   const EnvironmentVariableDirectory(String name, String what)
       : super(name, what);
 
   Future<Null> validate(String value) async {
     if (!await new Directory(value).exists()) notFound(value);
     return null;
   }
 
   notFound(String value) {
-    inputError(
+    deprecated_inputError(
         null,
         null,
         "The environment variable '$name' has the value "
         "'$value', that isn't a directory. $what");
   }
 }
 
 Future<bool> fileExists(Uri base, String path) async {
   return await new File.fromUri(base.resolve(path)).exists();
 }