Extend resolution Scope with ResolutionContext and set it for ResolverVisitor.

pkg/analyzer/test/generated/resolver_test.dart

Index: pkg/analyzer/test/generated/resolver_test.dart
diff --git a/pkg/analyzer/test/generated/resolver_test.dart b/pkg/analyzer/test/generated/resolver_test.dart
index f206be861752b7e78b419daca2cca6e3a562bf07..5f3a61c97af43b85b9121384e41dd700cf687476 100644
--- a/pkg/analyzer/test/generated/resolver_test.dart
+++ b/pkg/analyzer/test/generated/resolver_test.dart
@@ -1921,14 +1921,14 @@ class ElementResolverTest extends EngineTestCase {
     try {
       Scope outerScope = _visitor.nameScope_J2DAccessor as Scope;
       try {
-        _visitor.enclosingClass_J2DAccessor = enclosingClass;
+        _visitor.enclosingClass = enclosingClass;
         EnclosedScope innerScope = new ClassScope(
             new TypeParameterScope(outerScope, enclosingClass),
             enclosingClass);
         _visitor.nameScope_J2DAccessor = innerScope;
         node.accept(_resolver);
       } finally {
-        _visitor.enclosingClass_J2DAccessor = null;
+        _visitor.enclosingClass = null;
         _visitor.nameScope_J2DAccessor = outerScope;
       }
     } catch (exception) {