Use FastaMessage instead of String. Part 1.

pkg/front_end/lib/src/fasta/kernel/kernel_procedure_builder.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.kernel_procedure_builder;
 
 import 'package:front_end/src/fasta/kernel/kernel_shadow_ast.dart'
     show KernelProcedure;
 
 import 'package:front_end/src/fasta/source/source_library_builder.dart'
@@ skipping 28 matching lines @@
         TypeParameter,
         VariableDeclaration,
         VariableGet,
         VoidType,
         setParents;
 
 import 'package:kernel/type_algebra.dart' show containsTypeVariable, substitute;
 
 import '../deprecated_problems.dart' show deprecated_internalProblem;
 
-import '../messages.dart' show deprecated_warning;
+import '../messages.dart' show messageNonInstanceTypeVariableUse, warning;
 
 import '../loader.dart' show Loader;
 
 import 'kernel_builder.dart'
     show
         Builder,
         ClassBuilder,
         ConstructorReferenceBuilder,
         FormalParameterBuilder,
         KernelFormalParameterBuilder,
@@ skipping 84 matching lines @@
       List<TypeParameter> typeParameters = parent.target.typeParameters;
       if (typeParameters.isNotEmpty) {
         Map<TypeParameter, DartType> substitution;
         DartType removeTypeVariables(DartType type) {
           if (substitution == null) {
             substitution = <TypeParameter, DartType>{};
             for (TypeParameter parameter in typeParameters) {
               substitution[parameter] = const DynamicType();
             }
           }
-          deprecated_warning(fileUri, charOffset,
-              "Can only use type variables in instance methods.");
+          warning(messageNonInstanceTypeVariableUse, charOffset, fileUri);
           return substitute(type, substitution);
         }
 
         Set<TypeParameter> set = typeParameters.toSet();
         for (VariableDeclaration parameter in result.positionalParameters) {
           if (containsTypeVariable(parameter.type, set)) {
             parameter.type = removeTypeVariables(parameter.type);
           }
         }
         for (VariableDeclaration parameter in result.namedParameters) {
@@ skipping 245 matching lines @@
         }
       }
       initializers.add(initializer..parent = constructor);
       initializers.add(superInitializer);
       return;
     }
     initializers.add(initializer);
     initializer.parent = constructor;
   }
 }