More strong mode clean-up

pkg/analysis_server/test/services/search/search_engine_test.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 test.services.src.search.search_engine_internal;
 
 import 'dart:async';
 
 import 'package:analysis_server/src/services/index/index.dart';
 import 'package:analysis_server/src/services/search/search_engine.dart';
@@ skipping 18 matching lines @@
   final MatchKind kind;
   SourceRange range;
   final bool isResolved;
   final bool isQualified;
 
   ExpectedMatch(this.element, this.kind, int offset, int length,
       {this.isResolved: true, this.isQualified: false}) {
     this.range = new SourceRange(offset, length);
   }
 
-  bool operator ==(SearchMatch match) {
-    return match.element == this.element &&
+  bool operator ==(Object match) {
+    return match is SearchMatch &&
+        match.element == this.element &&
         match.kind == this.kind &&
         match.isResolved == this.isResolved &&
         match.isQualified == this.isQualified &&
         match.sourceRange == this.range;
   }
 
   @override
   String toString() {
     StringBuffer buffer = new StringBuffer();
     buffer.write("ExpectedMatch(kind=");
@@ skipping 847 matching lines @@
     List<SearchMatch> matches = await searchEngine.searchReferences(element);
     _assertMatches(matches, expectedMatches);
     expect(matches, hasLength(expectedMatches.length));
   }
 
   static void _assertMatches(
       List<SearchMatch> matches, List<ExpectedMatch> expectedMatches) {
     expect(matches, unorderedEquals(expectedMatches));
   }
 }