Emit json-rpc version in service protocol responses.

runtime/vm/json_stream.cc

 // 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.
 
 #include "platform/assert.h"
 
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
 #include "vm/json_stream.h"
 #include "vm/message.h"
@@ skipping 55 matching lines @@
     SetParams(param_keys_native, param_values_native, param_keys.Length());
   }
   if (FLAG_trace_service) {
     Isolate* isolate = Isolate::Current();
     ASSERT(isolate != NULL);
     const char* isolate_name = isolate->name();
     OS::Print("Isolate %s processing service request %s\n",
               isolate_name, method_);
     setup_time_micros_ = OS::GetCurrentTimeMicros();
   }
-  buffer_.Printf("{\"result\":");
+  buffer_.Printf("{\"json-rpc\":\"2.0\", \"result\":");
 }
 
 
 void JSONStream::SetupError() {
   buffer_.Clear();
-  buffer_.Printf("{\"error\":");
+  buffer_.Printf("{\"json-rpc\":\"2.0\", \"error\":");
 }
 
 
 static const char* GetJSONRpcErrorMessage(intptr_t code) {
   switch (code) {
     case kParseError:
       return "Parse error";
     case kInvalidRequest:
       return "Invalid Request";
     case kMethodNotFound:
@@ skipping 516 matching lines @@
   intptr_t len2 = OS::VSNPrint(p, len+1, format, args);
   va_end(args);
   ASSERT(len == len2);
   stream_->buffer_.AddChar('"');
   stream_->AddEscapedUTF8String(p);
   stream_->buffer_.AddChar('"');
   free(p);
 }
 
 }  // namespace dart