Remove unused API.

dart/sdk/lib/_internal/compiler/implementation/resolution/scope.dart

 // Copyright (c) 2012, 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.
 
 part of resolution;
 
 abstract class Scope {
   /**
    * Adds [element] to this scope. This operation is only allowed on mutable
    * scopes such as [MethodScope] and [BlockScope].
@@ skipping 16 matching lines @@
 
   NestedScope(this.parent);
 
   Element lookup(String name) {
     Element result = localLookup(name);
     if (result != null) return result;
     return parent.lookup(name);
   }
 
   Element localLookup(String name);
-
-  static Scope buildEnclosingScope(Element element) {
-    return element.enclosingElement != null
-        ? element.enclosingElement.buildScope() : element.buildScope();
-  }
 }
 
 class VariableDefinitionScope extends NestedScope {
   final String variableName;
   bool variableReferencedInInitializer = false;
 
   VariableDefinitionScope(Scope parent, this.variableName) : super(parent);
 
   Element localLookup(String name) {
     if (name == variableName) {
@@ skipping 120 matching lines @@
 
   Element localLookup(String name) => library.find(name);
   Element lookup(String name) => localLookup(name);
 
   Element add(Element newElement) {
     throw "Cannot add an element to a library scope";
   }
 
   String toString() => 'LibraryScope($library)';
 }