Support piping log data over the service protocol

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 16 matching lines @@
     kBreakpointAdded,
     kBreakpointResolved,
     kBreakpointRemoved,
     kInspect,
     kDebuggerSettingsUpdate,
 
     kGC,
 
     kEmbedder,
 
+    kLogging,
+
     kIllegal,
   };
 
   ServiceEvent(Isolate* isolate, EventKind event_kind)
       : isolate_(isolate),
         kind_(event_kind),
         embedder_kind_(NULL),
         embedder_stream_id_(NULL),
         breakpoint_(NULL),
         top_frame_(NULL),
@@ skipping 86 matching lines @@
     return bytes_length_;
   }
 
   void set_bytes(const uint8_t* bytes, intptr_t bytes_length) {
     bytes_ = bytes;
     bytes_length_ = bytes_length;
   }
 
   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 Object* exception_;
   const Object* async_continuation_;
   const Object* inspectee_;
   const Heap::GCStats* gc_stats_;
   const uint8_t* bytes_;
   intptr_t bytes_length_;
 };
 
 }  // namespace dart
 
 #endif  // VM_SERVICE_EVENT_H_