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

runtime/vm/service_event.h

 // 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.
 
 #ifndef VM_SERVICE_EVENT_H_
 #define VM_SERVICE_EVENT_H_
 
 #include "vm/debugger.h"
 
 class DebuggerEvent;
@@ skipping 23 matching lines @@
     kBreakpointRemoved,
     kInspect,
     kDebuggerSettingsUpdate,
 
     kGC,
 
     kEmbedder,
 
     kLogging,
 
+    kExtension,
+
     kIllegal,
   };
 
   struct LogRecord {
     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;
   };
 
+  struct ExtensionEvent {
+    const String* event_kind;
+    const String* event_data;
+  };
+
   ServiceEvent(Isolate* isolate, EventKind event_kind);
 
   explicit ServiceEvent(const DebuggerEvent* debugger_event);
 
   Isolate* isolate() const { return isolate_; }
 
   EventKind kind() const { return kind_; }
 
   const char* embedder_kind() const { return embedder_kind_; }
 
@@ skipping 87 matching lines @@
 
   void set_bytes(const uint8_t* bytes, intptr_t bytes_length) {
     bytes_ = bytes;
     bytes_length_ = bytes_length;
   }
 
   void set_log_record(const LogRecord& log_record) {
     log_record_ = log_record;
   }
 
+  void set_extension_event(const ExtensionEvent& extension_event) {
+    extension_event_ = extension_event;
+  }
+
   int64_t timestamp() const {
     return timestamp_;
   }
 
   void PrintJSON(JSONStream* js) const;
 
   void PrintJSONHeader(JSONObject* jsobj) const;
 
  private:
   Isolate* isolate_;
   EventKind kind_;
   const char* embedder_kind_;
   const char* embedder_stream_id_;
   Breakpoint* breakpoint_;
   ActivationFrame* top_frame_;
   const String* extension_rpc_;
   const Object* exception_;
   const Object* async_continuation_;
   bool at_async_jump_;
   const Object* inspectee_;
   const Heap::GCStats* gc_stats_;
   const uint8_t* bytes_;
   intptr_t bytes_length_;
   LogRecord log_record_;
+  ExtensionEvent extension_event_;
   int64_t timestamp_;
 };
 
 }  // namespace dart
 
 #endif  // VM_SERVICE_EVENT_H_