Move 'dart:profiler' contents into 'dart:developer' and remove 'dart:profiler'

tests/lib/developer/metrics_num_test.dart

 // Copyright (c) 2014, 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:profiler';
+import 'dart:developer';
 import 'package:expect/expect.dart';
 
 testGaugeDouble() {
   Expect.throws(() {
     // max argument is not a double
     gauge = new Gauge('test', 'alpha bravo', 1.0, 4);
   });
 }
 
 main() {
   testGaugeDouble();
 }