Check if the method / accessor being inlined is synthetic.

pkg/analysis_server/lib/src/services/refactoring/inline_method.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 services.src.refactoring.inline_method;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/protocol_server.dart' hide Element;
 import 'package:analysis_server/src/services/correction/source_range.dart';
@@ skipping 325 matching lines @@
     AstNode node = new NodeLocator.con1(offset).searchWithin(unit);
     if (node is! SimpleIdentifier) {
       return fatalStatus;
     }
     SimpleIdentifier identifier = node as SimpleIdentifier;
     // prepare selected ExecutableElement
     Element element = identifier.bestElement;
     if (element is! ExecutableElement) {
       return fatalStatus;
     }
+    if (element.isSynthetic) {
+      return fatalStatus;
+    }
     _methodElement = element as ExecutableElement;
     _isAccessor = element is PropertyAccessorElement;
     _methodUnit = element.unit;
     _methodUtils = new CorrectionUtils(_methodUnit);
     // class member
     bool isClassMember = element.enclosingElement is ClassElement;
     if (element is MethodElement || _isAccessor && isClassMember) {
       MethodDeclaration methodDeclaration = element.node;
       _methodNode = methodDeclaration;
       _methodParameters = methodDeclaration.parameters;
@@ skipping 481 matching lines @@
   }
 
   void _addVariable(SimpleIdentifier node) {
     VariableElement variableElement = getLocalVariableElement(node);
     if (variableElement != null) {
       SourceRange nodeRange = rangeNode(node);
       result.addVariable(variableElement, nodeRange);
     }
   }
 }