Flatten the if-else sequence.

pkg/analyzer/lib/src/generated/element_resolver.dart

 // Copyright (c) 2014, 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.
 
 library analyzer.src.generated.element_resolver;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 1082 matching lines @@
         !identical(element, enclosingClass)) {
       _resolver.errorReporter.reportErrorForNode(
           CompileTimeErrorCode.INVALID_CONSTRUCTOR_NAME, node);
       element = null;
     } else if (element == null ||
         (element is PrefixElement && !_isValidAsPrefix(node))) {
       // TODO(brianwilkerson) Recover from this error.
       if (_isConstructorReturnType(node)) {
         _resolver.errorReporter.reportErrorForNode(
             CompileTimeErrorCode.INVALID_CONSTRUCTOR_NAME, node);
+      } else if (parent is Annotation) {
+        _resolver.errorReporter.reportErrorForNode(
+            CompileTimeErrorCode.INVALID_ANNOTATION, parent);
+      } else if (element != null) {
+        _resolver.errorReporter.reportErrorForNode(
+            CompileTimeErrorCode.PREFIX_IDENTIFIER_NOT_FOLLOWED_BY_DOT,
+            node,
+            [element.name]);
+      } else if (node.name == "await" && _resolver.enclosingFunction != null) {
+        _recordUndefinedNode(
+            _resolver.enclosingClass,
+            StaticWarningCode.UNDEFINED_IDENTIFIER_AWAIT,
+            node,
+            [_resolver.enclosingFunction.displayName]);
       } else {
-        if (parent is Annotation) {
-          _resolver.errorReporter.reportErrorForNode(
-              CompileTimeErrorCode.INVALID_ANNOTATION, parent);
-        } else if (element != null) {
-          _resolver.errorReporter.reportErrorForNode(
-              CompileTimeErrorCode.PREFIX_IDENTIFIER_NOT_FOLLOWED_BY_DOT,
-              node,
-              [element.name]);
-        } else {
-          if (node.name == "await" && _resolver.enclosingFunction != null) {
-            _recordUndefinedNode(_resolver.enclosingClass,
-                StaticWarningCode.UNDEFINED_IDENTIFIER_AWAIT,
-                node,
-                [_resolver.enclosingFunction.displayName]);
-          } else {
-            _recordUndefinedNode(_resolver.enclosingClass,
-                StaticWarningCode.UNDEFINED_IDENTIFIER, node, [node.name]);
-          }
-        }
+        _recordUndefinedNode(_resolver.enclosingClass,
+            StaticWarningCode.UNDEFINED_IDENTIFIER, node, [node.name]);
       }
     }
     node.staticElement = element;
     if (node.inSetterContext() &&
         node.inGetterContext() &&
         enclosingClass != null) {
       InterfaceType enclosingType = enclosingClass.type;
       AuxiliaryElements auxiliaryElements = new AuxiliaryElements(
           _lookUpGetter(null, enclosingType, node.name), null);
       node.auxiliaryElements = auxiliaryElements;
@@ skipping 1464 matching lines @@
 
   @override
   Element get staticElement => null;
 
   @override
   dynamic/*=E*/ accept/*<E>*/(AstVisitor/*<E>*/ visitor) => null;
 
   @override
   void visitChildren(AstVisitor visitor) {}
 }