Restore "Add current rss and embedder name to Observatory"

runtime/observatory/lib/src/models/objects/vm.dart

Index: runtime/observatory/lib/src/models/objects/vm.dart
diff --git a/runtime/observatory/lib/src/models/objects/vm.dart b/runtime/observatory/lib/src/models/objects/vm.dart
index c71995e626f548295895e55bf45be6bef62cf9a1..b2bfd4de2a205dd01c19b472e01d552d65a97183 100644
--- a/runtime/observatory/lib/src/models/objects/vm.dart
+++ b/runtime/observatory/lib/src/models/objects/vm.dart
@@ -26,6 +26,8 @@ abstract class VM implements VMRef {
   /// The Dart VM version string.
   String get version;
 
+  String get embedder;
+
   /// The amount of memory currently allocated by native code in zones.
   int get nativeZoneMemoryUsage;
 
@@ -39,6 +41,7 @@ abstract class VM implements VMRef {
   int get heapAllocationCount;
 
   int get maxRSS;
+  int get currentRSS;
 
   /// The time that the VM started in milliseconds since the epoch.
   ///