Remove prepareTopLevelInference from base builder API

Change-Id: I87fd423c30c184e4775291a0a45176cba618d8e6
Reviewed-on: https://dart-review.googlesource.com/c/85710
Auto-Submit: Peter von der Ahé <ahe@google.com>
Commit-Queue: Dmitry Stefantsov <dmitryas@google.com>
Reviewed-by: Dmitry Stefantsov <dmitryas@google.com>
diff --git a/pkg/front_end/lib/src/fasta/builder/class_builder.dart b/pkg/front_end/lib/src/fasta/builder/class_builder.dart
index 8414d55..860d1cb 100644
--- a/pkg/front_end/lib/src/fasta/builder/class_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/class_builder.dart
@@ -145,8 +145,6 @@
         wasHandled: wasHandled, context: context);
   }
 
-  void prepareTopLevelInference() {}
-
   /// Find the first member of this class with [name]. This method isn't
   /// suitable for scope lookups as it will throw an error if the name isn't
   /// declared. The [scope] should be used for that. This method is used to
diff --git a/pkg/front_end/lib/src/fasta/builder/field_builder.dart b/pkg/front_end/lib/src/fasta/builder/field_builder.dart
index 8e780a5..054a552 100644
--- a/pkg/front_end/lib/src/fasta/builder/field_builder.dart
+++ b/pkg/front_end/lib/src/fasta/builder/field_builder.dart
@@ -28,6 +28,4 @@
   bool get isField => true;
 
   bool get hasTypeInferredFromInitializer;
-
-  void prepareTopLevelInference() {}
 }
diff --git a/pkg/front_end/lib/src/fasta/kernel/kernel_field_builder.dart b/pkg/front_end/lib/src/fasta/kernel/kernel_field_builder.dart
index 8e962cd..02010bd 100644
--- a/pkg/front_end/lib/src/fasta/kernel/kernel_field_builder.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/kernel_field_builder.dart
@@ -82,7 +82,6 @@
 
   Field get target => field;
 
-  @override
   void prepareTopLevelInference() {
     if (!isEligibleForInference) return;
     var typeInferrer = library.loader.typeInferenceEngine
diff --git a/pkg/front_end/lib/src/fasta/source/source_class_builder.dart b/pkg/front_end/lib/src/fasta/source/source_class_builder.dart
index 206b383..0c507c5 100644
--- a/pkg/front_end/lib/src/fasta/source/source_class_builder.dart
+++ b/pkg/front_end/lib/src/fasta/source/source_class_builder.dart
@@ -26,7 +26,6 @@
     show
         ConstructorReferenceBuilder,
         Declaration,
-        FieldBuilder,
         KernelClassBuilder,
         KernelFieldBuilder,
         KernelFunctionBuilder,
@@ -242,10 +241,9 @@
     constructorScopeBuilder.addMember(name, memberBuilder);
   }
 
-  @override
   void prepareTopLevelInference() {
     scope.forEach((String name, Declaration declaration) {
-      if (declaration is FieldBuilder) {
+      if (declaration is KernelFieldBuilder) {
         declaration.prepareTopLevelInference();
       }
     });
diff --git a/pkg/front_end/lib/src/fasta/source/source_loader.dart b/pkg/front_end/lib/src/fasta/source/source_loader.dart
index 5b41004..a330137 100644
--- a/pkg/front_end/lib/src/fasta/source/source_loader.dart
+++ b/pkg/front_end/lib/src/fasta/source/source_loader.dart
@@ -37,16 +37,6 @@
 
 import '../blacklisted_classes.dart' show blacklistedCoreClasses;
 
-import '../builder/builder.dart'
-    show
-        ClassBuilder,
-        Declaration,
-        EnumBuilder,
-        FieldBuilder,
-        LibraryBuilder,
-        NamedTypeBuilder,
-        TypeBuilder;
-
 import '../export.dart' show Export;
 
 import '../import.dart' show Import;
@@ -81,7 +71,16 @@
 import '../kernel/kernel_shadow_ast.dart'
     show ShadowClass, ShadowTypeInferenceEngine;
 
-import '../kernel/kernel_builder.dart' show KernelProcedureBuilder;
+import '../kernel/kernel_builder.dart'
+    show
+        ClassBuilder,
+        Declaration,
+        EnumBuilder,
+        KernelFieldBuilder,
+        KernelProcedureBuilder,
+        LibraryBuilder,
+        NamedTypeBuilder,
+        TypeBuilder;
 
 import '../kernel/kernel_target.dart' show KernelTarget;
 
@@ -929,7 +928,7 @@
         Iterator<Declaration> iterator = library.iterator;
         while (iterator.moveNext()) {
           Declaration member = iterator.current;
-          if (member is FieldBuilder) {
+          if (member is KernelFieldBuilder) {
             member.prepareTopLevelInference();
           }
         }