add memory usage to the diagnostics page

pkg/analysis_server/test/src/utilities/profiling_test.dart

Index: pkg/analysis_server/test/src/utilities/profiling_test.dart
diff --git a/pkg/analysis_server/test/src/utilities/profiling_test.dart b/pkg/analysis_server/test/src/utilities/profiling_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..4906c4bc7b7acfec8caac0d48c59d53baaa14012
--- /dev/null
+++ b/pkg/analysis_server/test/src/utilities/profiling_test.dart
@@ -0,0 +1,30 @@
+// Copyright (c) 2017, 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.
+
+import 'dart:io';
+
+import 'package:analysis_server/src/utilities/profiling.dart';
+import 'package:test/test.dart';
+
+main() {
+  group('ProcessProfiler', () {
+    // Skip on windows.
+    if (Platform.isWindows) {
+      return;
+    }
+
+    test('getProfilerForPlatform', () async {
+      expect(ProcessProfiler.getProfilerForPlatform(), isNotNull);
+    });
+
+    test('getProcessUsage', () async {
+      ProcessProfiler profiler = ProcessProfiler.getProfilerForPlatform();
+      UsageInfo info = await profiler.getProcessUsage(pid);
+
+      expect(info, isNotNull);
+      expect(info.cpuPercentage, greaterThanOrEqualTo(0.0));
+      expect(info.memoryKB, greaterThanOrEqualTo(0));
+    });
+  });
+}