Update analysis server and integration tests to match new ChangeContentOverlay.

pkg/analysis_services/test/correction/fix_test.dart

Index: pkg/analysis_services/test/correction/fix_test.dart
diff --git a/pkg/analysis_services/test/correction/fix_test.dart b/pkg/analysis_services/test/correction/fix_test.dart
index 3d672fc96c6e008fa8ef229e058aa77268558015..476f3196e9faf4d0ca7486f2eb8a1af62db059f5 100644
--- a/pkg/analysis_services/test/correction/fix_test.dart
+++ b/pkg/analysis_services/test/correction/fix_test.dart
@@ -41,7 +41,9 @@ class FixProcessorTest extends AbstractSingleUnitTest {
     // 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);
   }
@@ -1799,16 +1801,6 @@ main() {
 ''');
   }
 
-  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.
    */