Include 'fixedId' key when printing service ids

runtime/vm/json_stream.cc

Index: runtime/vm/json_stream.cc
diff --git a/runtime/vm/json_stream.cc b/runtime/vm/json_stream.cc
index 2ed62efd8c1caf16ed1ab3bfaa4e79f129dc22e6..e1cf409b64961394802fc5e9f24cab7b12c9d8c5 100644
--- a/runtime/vm/json_stream.cc
+++ b/runtime/vm/json_stream.cc
@@ -357,9 +357,9 @@ void JSONStream::PrintValue(Isolate* isolate, bool ref) {
 }
 
 
-void JSONStream::PrintServiceId(const char* name, const Object& o) {
+void JSONStream::PrintServiceId(const Object& o) {
   ASSERT(id_zone_ != NULL);
-  PrintProperty(name, id_zone_->GetServiceId(o));
+  PrintProperty("id", id_zone_->GetServiceId(o));
 }
 
 
@@ -558,6 +558,27 @@ JSONObject::JSONObject(const JSONArray* arr) : stream_(arr->stream_) {
 }
 
 
+void JSONObject::AddFixedServiceId(const char* format, ...) const {
+  // Mark that this id is fixed.
+  AddProperty("fixedId", true);
+  // Add the id property.
+  stream_->PrintPropertyName("id");
+  va_list args;
+  va_start(args, format);
+  intptr_t len = OS::VSNPrint(NULL, 0, format, args);
+  va_end(args);
+  char* p = reinterpret_cast<char*>(malloc(len+1));
+  va_start(args, format);
+  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);
+}
+
+
 void JSONObject::AddPropertyF(const char* name,
                               const char* format, ...) const {
   stream_->PrintPropertyName(name);