Revert "Do nothing if [changeFile] reported, but the file content is the same."

pkg/analyzer/test/src/dart/analysis/driver_test.dart

 // Copyright (c) 2016, 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.test.driver;
 
 import 'dart:async';
 import 'dart:convert';
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 59 matching lines @@
         provider,
         byteStore,
         contentCache,
         new SourceFactory([
           new DartUriResolver(sdk),
           new PackageMapUriResolver(provider, <String, List<Folder>>{
             'test': [provider.getFolder(testProject)]
           })
         ], null, provider),
         new AnalysisOptionsImpl()..strongMode = true);
-    driver.status.listen((status) {
+    driver.status.lastWhere((status) {
       allStatuses.add(status);
       if (status.isIdle) {
         idleStatusMonitor.notify();
       }
     });
     driver.results.listen(allResults.add);
   }
 
   test_addFile_thenRemove() async {
     var a = _p('/test/lib/a.dart');
@@ skipping 43 matching lines @@
     // While "b" is not analyzed explicitly, it is analyzed implicitly.
     // The change causes "a" to be reanalyzed.
     await _waitForIdle();
     expect(allResults, hasLength(1));
     {
       AnalysisResult ar = allResults.firstWhere((r) => r.path == a);
       expect(_getTopLevelVarType(ar.unit, 'A'), 'double');
     }
   }
 
-  test_changeFile_noContentChange_noNewResult() async {
-    _addTestFile('main() {}', priority: true);
-
-    // Initial analysis.
-    await _waitForIdle();
-    expect(allResults, hasLength(1));
-
-    // Update the file, but don't notify the driver.
-    // Don't update the file in the file system.
-    // But tell the driver the the file was changed.
-    // The driver should eventually check the file and ignore.
-    allStatuses.clear();
-    allResults.clear();
-    driver.changeFile(testFile);
-
-    // The driver switched to analysis and back to idle.
-    await _waitForIdle();
-    expect(allStatuses, hasLength(2));
-    expect(allStatuses.map((status) => status.isAnalyzing), [true, false]);
-
-    // No new results.
-    expect(allResults, isEmpty);
-  }
-
   test_changeFile_selfConsistent() async {
     var a = _p('/test/lib/a.dart');
     var b = _p('/test/lib/b.dart');
     provider.newFile(
         a,
         r'''
 import 'b.dart';
 var A1 = 1;
 var A2 = B1;
 ''');
@@ skipping 387 matching lines @@
   @override
   List<int> get(String key) {
     return map[key];
   }
 
   @override
   void put(String key, List<int> bytes) {
     map[key] = bytes;
   }
 }