Simplify various name flavors in VM.

runtime/vm/debugger.cc

Index: runtime/vm/debugger.cc
diff --git a/runtime/vm/debugger.cc b/runtime/vm/debugger.cc
index 06e788026781b828c52f60a0e7291ebd62a41adf..8d614a63760850464cf43c7e331bcf64bbbf71a1 100644
--- a/runtime/vm/debugger.cc
+++ b/runtime/vm/debugger.cc
@@ -1056,7 +1056,7 @@ RawObject* ActivationFrame::Evaluate(const String& expr) {
     VariableAt(i, &name, &ignore, &ignore, &value);
     if (!name.Equals(Symbols::This())) {
       if (IsPrivateVariableName(name)) {
-        name = String::IdentifierPrettyName(name);
+        name = String::ScrubName(name);
       }
       param_names.Add(name);
       param_values.Add(value);
@@ -1129,7 +1129,7 @@ void ActivationFrame::PrintToJSONObject(JSONObject* jsobj,
       if (var_name.raw() != Symbols::AsyncOperation().raw()) {
         JSONObject jsvar(&jsvars);
         jsvar.AddProperty("type", "BoundVariable");
-        var_name = String::IdentifierPrettyName(var_name);
+        var_name = String::ScrubName(var_name);
         jsvar.AddProperty("name", var_name.ToCString());
         jsvar.AddProperty("value", var_value, !full);
         // TODO(turnidge): Do we really want to provide this on every