Restore "Add current rss and embedder name to Observatory"

runtime/vm/os_fuchsia.cc

Index: runtime/vm/os_fuchsia.cc
diff --git a/runtime/vm/os_fuchsia.cc b/runtime/vm/os_fuchsia.cc
index 3781f029ba27e3b84a1af3cf654ee12c4d41e387..11e795192f7d6e9803ade7e0e7967f9ca52227b6 100644
--- a/runtime/vm/os_fuchsia.cc
+++ b/runtime/vm/os_fuchsia.cc
@@ -136,16 +136,6 @@ int OS::NumberOfAvailableProcessors() {
   return sysconf(_SC_NPROCESSORS_CONF);
 }
 
-uintptr_t OS::MaxRSS() {
-  mx_info_task_stats_t task_stats;
-  mx_handle_t process = mx_process_self();
-  mx_status_t status = mx_object_get_info(
-      process, MX_INFO_TASK_STATS, &task_stats, sizeof(task_stats), NULL, NULL);
-  return (status == MX_OK)
-             ? (task_stats.mem_private_bytes + task_stats.mem_shared_bytes)
-             : 0;
-}
-
 void OS::Sleep(int64_t millis) {
   SleepMicros(millis * kMicrosecondsPerMillisecond);
 }