Rewrite mixin application handling in Fasta.

pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart

Index: pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart b/pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart
index 94e62ffc6406ee073d19445df8d25f03b8eb9fea..873c3246a15e433f7712c50e29408bcf2dc7f7a3 100644
--- a/pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/kernel_named_type_builder.dart
@@ -10,15 +10,10 @@ import '../messages.dart' show warning;
 
 import 'kernel_builder.dart'
     show
-        Builder,
-        ClassBuilder,
-        DynamicTypeBuilder,
         KernelClassBuilder,
         KernelInvalidTypeBuilder,
         KernelTypeBuilder,
         LibraryBuilder,
-        MixinApplicationBuilder,
-        NamedMixinApplicationBuilder,
         NamedTypeBuilder,
         TypeBuilder,
         TypeVariableBuilder;
@@ -93,57 +88,4 @@ class KernelNamedTypeBuilder
     }
     return this;
   }
-
-  @override
-  TypeBuilder computeMixin(
-      Uri fileUri, int charOffset, LibraryBuilder library) {
-    if (false && builder is NamedMixinApplicationBuilder) {
-      NamedMixinApplicationBuilder builder = this.builder;
-      var superclass = builder.mixinApplication.mixins.last;
-      while (superclass is MixinApplicationBuilder) {
-        superclass = superclass.mixins.last;
-      }
-      KernelTypeBuilder dynamicType =
-          new KernelNamedTypeBuilder("dynamic", null, charOffset, fileUri)
-            ..bind(new DynamicTypeBuilder(const DynamicType(), library, -1));
-      Map<TypeVariableBuilder, TypeBuilder> substitution =
-          builder.getSubstitutionMap(
-              superclass.builder, fileUri, charOffset, dynamicType);
-      if (substitution != null) {
-        superclass = superclass.subst(substitution);
-      }
-      if (builder.typeVariables != null) {
-        substitution = <TypeVariableBuilder, TypeBuilder>{};
-        List<KernelTypeBuilder> arguments =
-            this.arguments ?? const <KernelTypeBuilder>[];
-        for (int i = 0; i < builder.typeVariables.length; i++) {
-          KernelTypeBuilder argument =
-              i < arguments.length ? arguments[i] : dynamicType;
-          substitution[builder.typeVariables[i]] = argument;
-        }
-        superclass = superclass.subst(substitution);
-      }
-      return superclass;
-    }
-    if (builder is ClassBuilder) {
-      // ignore: INVALID_ASSIGNMENT
-      ClassBuilder cls = builder;
-      for (Builder constructory in cls.constructors.local.values) {
-        if (constructory.isConstructor && !constructory.isSynthetic) {
-          library.addCompileTimeError(
-              charOffset,
-              "Can't use '$fullNameForErrors' as a mixin because it has "
-              "constructors.",
-              fileUri: fileUri);
-          library.addCompileTimeError(
-              constructory.charOffset,
-              "This constructor prevents using '$fullNameForErrors' as a "
-              "mixin.",
-              fileUri: builder.fileUri);
-        }
-      }
-      return this;
-    }
-    return super.computeMixin(fileUri, charOffset, library);
-  }
 }