Update analysis server and integration tests to match new ChangeContentOverlay.

pkg/analysis_services/test/correction/fix_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.correction.fix;
 
 import 'package:analysis_services/correction/change.dart';
 import 'package:analysis_services/correction/fix.dart';
 import 'package:analysis_services/index/index.dart';
 import 'package:analysis_services/index/local_memory_index.dart';
@@ skipping 23 matching lines @@
   Change change;
   String resultCode;
 
   void assertHasFix(FixKind kind, String expected) {
     AnalysisError error = _findErrorToFix();
     fix = _assertHasFix(kind, error);
     change = fix.change;
     // apply to "file"
     List<FileEdit> fileEdits = change.fileEdits;
     expect(fileEdits, hasLength(1));
-    resultCode = _applyEdits(testCode, change.fileEdits[0].edits);
+    // TODO(paulberry): should the code under test be responsible for sorting
+    // the edits?
+    resultCode = Edit.applySorted(testCode, change.fileEdits[0].edits);
     // verify
     expect(resultCode, expected);
   }
 
   void assertHasPositionGroup(String id, List<Position> expectedPositions) {
     List<LinkedEditGroup> linkedPositionGroups = change.linkedEditGroups;
     for (LinkedEditGroup group in linkedPositionGroups) {
       if (group.id == id) {
         expect(group.positions, unorderedEquals(expectedPositions));
         return;
@@ skipping 1737 matching lines @@
 ''');
     assertHasFix(FixKind.USE_EFFECTIVE_INTEGER_DIVISION, '''
 main() {
   var a = 5;
   var b = 2;
   print(a ~/ b);
 }
 ''');
   }
 
-  String _applyEdits(String code, List<Edit> edits) {
-    edits.sort((a, b) => b.offset - a.offset);
-    edits.forEach((Edit edit) {
-      code = code.substring(0, edit.offset) +
-          edit.replacement +
-          code.substring(edit.end);
-    });
-    return code;
-  }
-
   /**
    * Computes fixes and verifies that there is a fix of the given kind.
    */
   Fix _assertHasFix(FixKind kind, AnalysisError error) {
     List<Fix> fixes = computeFixes(searchEngine, testUnit, error);
     for (Fix fix in fixes) {
       if (fix.kind == kind) {
         return fix;
       }
     }
@@ skipping 59 matching lines @@
       positions.add(new Position(testFile, offset));
     }
     return positions;
   }
 
   void _indexTestUnit(String code) {
     resolveTestUnit(code);
     index.indexUnit(context, testUnit);
   }
 }