Refactor computation of NativeBehavior.

pkg/compiler/lib/src/kernel/world_builder.dart

 // Copyright (c) 2017, 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.
 
 import 'package:kernel/ast.dart' as ir;
 
 import '../common.dart';
 import '../common/names.dart';
 import '../core_types.dart';
 import '../elements/elements.dart';
@@ skipping 233 matching lines @@
     // TODO(johnniwinther): Add the type argument to the list literal when we
     // no longer use resolution types.
     return new InterfaceType(
         cls,
         new List/*<DartType>*/ .filled(
             node.typeParameters.length, const DynamicType()));
   }
 
   @override
   native.NativeBehavior getNativeBehaviorForMethod(ir.Procedure procedure) {
-    throw new UnimplementedError('KernelWorldBuilder.getDartType');
+    throw new UnimplementedError(
+        'KernelWorldBuilder.getNativeBehaviorForMethod');
   }
 
   @override
   native.NativeBehavior getNativeBehaviorForFieldStore(ir.Field field) {
-    throw new UnimplementedError('KernelWorldBuilder.getDartType');
+    throw new UnimplementedError(
+        'KernelWorldBuilder.getNativeBehaviorForFieldStore');
   }
 
   @override
   native.NativeBehavior getNativeBehaviorForFieldLoad(ir.Field field) {
-    throw new UnimplementedError('KernelWorldBuilder.getDartType');
+    throw new UnimplementedError(
+        'KernelWorldBuilder.getNativeBehaviorForFieldLoad');
   }
 
   LibraryEntity getLibrary(ir.Library node) => _getLibrary(node);
 
   @override
   Local getLocalFunction(ir.TreeNode node) => _getLocal(node);
 
   @override
   ClassEntity getClass(ir.Class node) => _getClass(node);
 
@@ skipping 334 matching lines @@
     }
     return builder._getLibrary(library);
   }
 
   KLibrary getLibraryForFunction(KFunction function) =>
       _getLibrary(function, builder._methodMap);
 
   KLibrary getLibraryForField(KField field) =>
       _getLibrary(field, builder._fieldMap);
 }