Implement type variables in mixin applications.

pkg/front_end/lib/src/fasta/source/outline_builder.dart

Index: pkg/front_end/lib/src/fasta/source/outline_builder.dart
diff --git a/pkg/front_end/lib/src/fasta/source/outline_builder.dart b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
index e010ea9c30705b6e6a40705ca2eacedef4c4934d..81312dab0cdedfa108488567162d5b9c45d9448e 100644
--- a/pkg/front_end/lib/src/fasta/source/outline_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/outline_builder.dart
@@ -210,6 +210,10 @@ class OutlineBuilder extends UnhandledListener {
     TypeBuilder supertype = pop();
     List<TypeVariableBuilder> typeVariables = pop();
     String name = pop();
+    if (typeVariables != null && supertype is MixinApplicationBuilder) {
+      supertype.typeVariables = typeVariables;
+      supertype.subclassName = name;
+    }
     int modifiers = Modifier.validate(pop());
     List<MetadataBuilder> metadata = pop();
     library.addClass(metadata, modifiers, name, typeVariables, supertype,
@@ -321,6 +325,10 @@ class OutlineBuilder extends UnhandledListener {
     TypeBuilder mixinApplication = pop();
     List<TypeVariableBuilder> typeVariables = pop();
     String name = pop();
+    if (typeVariables != null && mixinApplication is MixinApplicationBuilder) {
+      mixinApplication.typeVariables = typeVariables;
+      mixinApplication.subclassName = name;
+    }
     int modifiers = Modifier.validate(pop());
     List<MetadataBuilder> metadata = pop();
     library.addNamedMixinApplication(