Fix tid recorded in dart tracing helper to be an integer.

mojo/common/dart/lib/tracing_helper.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 library tracing;
 
 import 'trace_provider_impl.dart';
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:core';
 import 'dart:io';
 import 'dart:isolate';
 
 import 'package:mojo/application.dart';
 import 'package:mojo/bindings.dart';
 import 'package:mojo/core.dart';
 import 'package:mojo_services/tracing/tracing.mojom.dart';
 
 // TracingHelper is used by Dart code running in the Mojo shell in order
 // to perform tracing.
 class TracingHelper {
   TraceProviderImpl _impl;
-  String _tid;
+  int _tid;
 
   // Construct an instance of TracingHelper from within your application's
   // |initialize()| method. |appName| will be used to form a thread identifier
   // for use in trace messages. If |appName| is longer than 20 characters then
   // only the last 20 characters of |appName| will be used.
   TracingHelper(Application app, String appName) {
     // We use only the last 20 characters of appName to form the tid so that
     // the 9-digit Isolate hash code we are appending won't get truncated by the
     // tracing UI.
     if (appName.length > 20) {
       appName = appName.substring(appName.length - 20);
     }
-    _tid = "${appName}/${Isolate.current.hashCode.toString()}";
+    _tid = Isolate.current.hashCode;

[qsr, 2015/09/08 12:38:54]

Can you mix the hashCode of the appName someway?

[ppi, 2015/09/08 16:42:50]

Done.

     ApplicationConnection connection = app.connectToApplication("mojo:tracing");
     connection.provideService(TraceProviderName, (e) {
       assert(_impl == null);
       _impl = new TraceProviderImpl.fromEndpoint(e);
     });
   }
 
   bool isActive() {
     return (_impl != null) && _impl.isActive();
   }
@@ skipping 55 matching lines @@
 
   _FunctionTraceImpl(this._tracing, this._functionName, this._categories);
 
   @override
   void end() {
     if (_functionName != null) {
       _tracing._endFunction(_functionName, _categories);
     }
   }
 }