Clear analyzer warning on Observatory

runtime/observatory/tests/service/get_native_allocation_samples_test.dart

Index: runtime/observatory/tests/service/get_native_allocation_samples_test.dart
diff --git a/runtime/observatory/tests/service/get_native_allocation_samples_test.dart b/runtime/observatory/tests/service/get_native_allocation_samples_test.dart
index c09d6937d0ecdcef866c975408231deaf15df608..10bb7f2ebde4d3ba43d51795286ccd6c6ab47446 100644
--- a/runtime/observatory/tests/service/get_native_allocation_samples_test.dart
+++ b/runtime/observatory/tests/service/get_native_allocation_samples_test.dart
@@ -3,7 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 // VMOptions=--error_on_bad_type --error_on_bad_override
 
-import 'package:observatory/cpu_profile.dart';
+import 'package:observatory/sample_profile.dart';
 import 'package:observatory/models.dart' as M;
 import 'package:observatory/service_io.dart';
 import 'package:unittest/unittest.dart';
@@ -57,7 +57,7 @@ var tests = [
   (VM vm) async {
     var response =
         await vm.invokeRpc('_getNativeAllocationSamples', {'tags': 'None'});
-    CpuProfile cpuProfile = new CpuProfile();
+    SampleProfile cpuProfile = new SampleProfile();
     await cpuProfile.load(vm, response);
     var codeTree = cpuProfile.loadCodeTree(M.ProfileTreeDirection.inclusive);
     var functionTree =
@@ -69,7 +69,7 @@ var tests = [
   (VM vm) async {
     var response =
         await vm.invokeRpc('_getNativeAllocationSamples', {'tags': 'None'});
-    CpuProfile cpuProfile = new CpuProfile();
+    SampleProfile cpuProfile = new SampleProfile();
     await cpuProfile.load(vm, response);
     var codeTreeExclusive =
         cpuProfile.loadCodeTree(M.ProfileTreeDirection.exclusive);