Handle Native("...") annotations in KernelBehaviorBuilder.

pkg/compiler/lib/src/core_types.dart

Index: pkg/compiler/lib/src/core_types.dart
diff --git a/pkg/compiler/lib/src/core_types.dart b/pkg/compiler/lib/src/core_types.dart
index 81eeacdcc0bf7f5f0233084cfd9f26001e021d6e..f69355d1a985953f0a0af759ee076ac1b20fb2e2 100644
--- a/pkg/compiler/lib/src/core_types.dart
+++ b/pkg/compiler/lib/src/core_types.dart
@@ -77,13 +77,6 @@ abstract class CommonElements {
   /// The `NativeTypedData` class from dart:typed_data.
   ClassEntity get typedDataClass;
 
-  // TODO(johnniwinther): Move this to the JavaScriptBackend.
-  /// The class for patch annotation defined in dart:_js_helper.
-  ClassEntity get patchAnnotationClass;
-
-  // TODO(johnniwinther): Move this to the JavaScriptBackend.
-  ClassEntity get nativeAnnotationClass;
-
   /// Constructor of the `Symbol` class. This getter will ensure that `Symbol`
   /// is resolved and lookup the constructor on demand.
   ConstructorEntity get symbolConstructor;