[vm, gardening] Move --trace-service output to stderr.

runtime/lib/vmservice.cc

 // 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.
 
 #include "vm/bootstrap_natives.h"
 #include "vm/dart_api_impl.h"
 #include "vm/datastream.h"
 #include "vm/exceptions.h"
 #include "vm/flags.h"
 #include "vm/growable_array.h"
@@ skipping 65 matching lines @@
     const String& name = String::Handle(String::New(isolate->name()));
     ASSERT(!name.IsNull());
     const Array& args = Array::Handle(Array::New(3));
     ASSERT(!args.IsNull());
     args.SetAt(0, port_int);
     args.SetAt(1, send_port);
     args.SetAt(2, name);
     const Object& r =
         Object::Handle(DartEntry::InvokeFunction(register_function_, args));
     if (FLAG_trace_service) {
-      OS::Print("vm-service: Isolate %s %" Pd64 " registered.\n",
-                name.ToCString(), port_id);
+      OS::PrintErr("vm-service: Isolate %s %" Pd64 " registered.\n",
+                   name.ToCString(), port_id);
     }
     ASSERT(!r.IsError());
   }
 
  private:
   Function& register_function_;
   Isolate* service_isolate_;
 };
 #endif  // !PRODUCT
 
@@ skipping 30 matching lines @@
 DEFINE_NATIVE_ENTRY(VMService_SendObjectRootServiceMessage, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(Array, message, arguments->NativeArgAt(0));
   if (FLAG_support_service) {
     return Service::HandleObjectRootMessage(message);
   }
   return Object::null();
 }
 
 DEFINE_NATIVE_ENTRY(VMService_OnStart, 0) {
   if (FLAG_trace_service) {
-    OS::Print("vm-service: Booting dart:vmservice library.\n");
+    OS::PrintErr("vm-service: Booting dart:vmservice library.\n");
   }
   // Boot the dart:vmservice library.
   ServiceIsolate::BootVmServiceLibrary();
   if (!FLAG_support_service) {
     return Object::null();
   }
 #ifndef PRODUCT
   // Register running isolates with service.
   RegisterRunningIsolatesVisitor register_isolates(thread);
   if (FLAG_trace_service) {
-    OS::Print("vm-service: Registering running isolates.\n");
+    OS::PrintErr("vm-service: Registering running isolates.\n");
   }
   Isolate::VisitIsolates(&register_isolates);
 #endif
   return Object::null();
 }
 
 DEFINE_NATIVE_ENTRY(VMService_OnExit, 0) {
   if (FLAG_trace_service) {
-    OS::Print("vm-service: processed exit message.\n");
+    OS::PrintErr("vm-service: processed exit message.\n");
     MessageHandler* message_handler = isolate->message_handler();
-    OS::Print("vm-service: live ports = %" Pd "\n",
-              message_handler->live_ports());
+    OS::PrintErr("vm-service: live ports = %" Pd "\n",
+                 message_handler->live_ports());
   }
   return Object::null();
 }
 
 DEFINE_NATIVE_ENTRY(VMService_OnServerAddressChange, 1) {
   if (!FLAG_support_service) {
     return Object::null();
   }
   GET_NATIVE_ARGUMENT(String, address, arguments->NativeArgAt(0));
   if (address.IsNull()) {
@@ skipping 292 matching lines @@
     ServiceEvent spawn_event(NULL, ServiceEvent::kIsolateSpawn);
     spawn_event.set_spawn_token(&token);
     spawn_event.set_spawn_error(&String::Cast(result));
     Service::HandleEvent(&spawn_event);
   }
 #endif  // PRODUCT
   return Object::null();
 }
 
 }  // namespace dart