Add error condition INVALID_OVERLAY_CHANGE to analysis server.

pkg/analysis_server/test/domain_analysis_test.dart

Index: pkg/analysis_server/test/domain_analysis_test.dart
diff --git a/pkg/analysis_server/test/domain_analysis_test.dart b/pkg/analysis_server/test/domain_analysis_test.dart
index bfd7ab9bfcf8bf100bc0d475655483cb62112b6d..a2d0e81a0cdb6148f6a9b8a6be0a9088678913cb 100644
--- a/pkg/analysis_server/test/domain_analysis_test.dart
+++ b/pkg/analysis_server/test/domain_analysis_test.dart
@@ -262,6 +262,36 @@ testUpdateContent() {
       });
     });
   });
+
+  group('out of range', () {
+    Future outOfRangeTest(SourceEdit edit) {
+      AnalysisTestHelper helper = new AnalysisTestHelper();
+      helper.createSingleFileProject('library A;');
+      return helper.waitForOperationsFinished().then((_) {
+        helper.sendContentChange(new AddContentOverlay('library B;'));
+        return helper.waitForOperationsFinished().then((_) {
+          ChangeContentOverlay contentChange = new ChangeContentOverlay([edit]);
+          Request request = new AnalysisUpdateContentParams({
+            helper.testFile: contentChange}).toRequest('0');
+          Response response = helper.handler.handleRequest(request);
+          expect(response, isResponseFailure('0',
+              RequestErrorCode.INVALID_OVERLAY_CHANGE));
+        });
+      });
+    }
+
+    test('negative length', () {
+      return outOfRangeTest(new SourceEdit(3, -1, 'foo'));
+    });
+
+    test('negative offset', () {
+      return outOfRangeTest(new SourceEdit(-1, 3, 'foo'));
+    });
+
+    test('beyond end', () {
+      return outOfRangeTest(new SourceEdit(6, 6, 'foo'));
+    });
+  });
 }