Add dart:developer.postEvent for posting events to the service protocol from Dart code

runtime/vm/service.h

 // Copyright (c) 2013, 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.
 
 #ifndef VM_SERVICE_H_
 #define VM_SERVICE_H_
 
 #include "include/dart_tools_api.h"
 
 #include "vm/allocation.h"
@@ skipping 106 matching lines @@
   static void SendLogEvent(Isolate* isolate,
                            int64_t sequence_number,
                            int64_t timestamp,
                            intptr_t level,
                            const String& name,
                            const String& message,
                            const Instance& zone,
                            const Object& error,
                            const Instance& stack_trace);
 
+  static void SendExtensionEvent(Isolate* isolate,
+                                 const String& event_kind,
+                                 const String& event_data);
+
   static void PostError(const String& method_name,
                         const Array& parameter_keys,
                         const Array& parameter_values,
                         const Instance& reply_port,
                         const Instance& id,
                         const Error& error);
 
   // Well-known streams.
   static StreamInfo vm_stream;
   static StreamInfo isolate_stream;
   static StreamInfo debug_stream;
   static StreamInfo gc_stream;
   static StreamInfo echo_stream;
   static StreamInfo graph_stream;
   static StreamInfo logging_stream;
+  static StreamInfo extension_stream;
 
   static bool ListenStream(const char* stream_id);
   static void CancelStream(const char* stream_id);
 
   static RawObject* RequestAssets();
 
   static Dart_ServiceStreamListenCallback stream_listen_callback() {
     return stream_listen_callback_;
   }
   static Dart_ServiceStreamCancelCallback stream_cancel_callback() {
@@ skipping 40 matching lines @@
   static bool needs_isolate_events_;
   static bool needs_debug_events_;
   static bool needs_gc_events_;
   static bool needs_echo_events_;
   static bool needs_graph_events_;
 };
 
 }  // namespace dart
 
 #endif  // VM_SERVICE_H_