Clear analyzer warning on Observatory

runtime/observatory/lib/cpu_profile.dart

Index: runtime/observatory/lib/cpu_profile.dart
diff --git a/runtime/observatory/lib/cpu_profile.dart b/runtime/observatory/lib/cpu_profile.dart
deleted file mode 100644
index ccc53c5293fbbc6ae5023deb0cc7465ec97f7db7..0000000000000000000000000000000000000000
--- a/runtime/observatory/lib/cpu_profile.dart
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright (c) 2015, 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 cpu_profiler;
-
-import 'dart:async';
-import 'dart:typed_data';
-import 'package:observatory/models.dart' as M;
-import 'package:observatory/service.dart';
-import 'package:observatory/utils.dart';
-
-part 'src/cpu_profile/cpu_profile.dart';