De-mangle private identifiers returned by the debugger API.

runtime/vm/debugger.cc

Index: runtime/vm/debugger.cc
diff --git a/runtime/vm/debugger.cc b/runtime/vm/debugger.cc
index c39c3e4f2b630b6912cfc00bef343f6a860c3223..ada26ee722e44c7bd319243b4f62949902004a5d 100644
--- a/runtime/vm/debugger.cc
+++ b/runtime/vm/debugger.cc
@@ -1750,6 +1750,7 @@ RawArray* Debugger::GetInstanceFields(const Instance& obj) {
         field_name = field.name();
         field_list.Add(field_name);
         field_value = GetInstanceField(cls, field_name, obj);
+        field_name = String::IdentifierPrettyName(field_name);
         field_list.Add(field_value);
       }
     }
@@ -1771,6 +1772,7 @@ RawArray* Debugger::GetStaticFields(const Class& cls) {
     if (field.is_static()) {
       field_name = field.name();
       field_value = GetStaticField(cls, field_name);
+      field_name = String::IdentifierPrettyName(field_name);
       field_list.Add(field_name);
       field_list.Add(field_value);
     }
@@ -1804,6 +1806,7 @@ void Debugger::CollectLibraryFields(const GrowableObjectArray& field_list,
       if (!prefix.IsNull()) {
         field_name = String::Concat(prefix, field_name);
       }
+      field_name = String::IdentifierPrettyName(field_name);
       field_list.Add(field_name);
       field_list.Add(field_value);
     }