Access to imports in the VM's runtime mirrors. Extend test coverage of the source mirrors.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 3ea8065e7c466591b6faab27acfb3577ab8845cf..422919bae22f74f218768d8351688e348189cf16 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -8953,6 +8953,45 @@ void LibraryPrefix::PrintToJSONStream(JSONStream* stream, bool ref) const {
 }
 
 
+void Namespace::set_metadata_field(const Field& value) const {
+  StorePointer(&raw_ptr()->metadata_field_, value.raw());
+}
+
+
+void Namespace::AddMetadata(intptr_t token_pos, const Class& owner_class) {
+  ASSERT(Field::Handle(metadata_field()).IsNull());
+  Field& field = Field::Handle(Field::New(Symbols::TopLevel(),
+                                          true,   // is_static
+                                          false,  // is_final
+                                          false,  // is_const
+                                          owner_class,
+                                          token_pos));
+  field.set_type(Type::Handle(Type::DynamicType()));
+  field.set_value(Array::empty_array());
+  set_metadata_field(field);
+}
+
+
+RawObject* Namespace::GetMetadata() const {
+  Field& field = Field::Handle(metadata_field());
+  if (field.IsNull()) {
+    // There is no metadata for this object.
+    return Object::empty_array().raw();
+  }
+  Object& metadata = Object::Handle();
+  metadata = field.value();
+  if (field.value() == Object::empty_array().raw()) {
+    metadata = Parser::ParseMetadata(Class::Handle(field.owner()),
+                                     field.token_pos());
+    if (metadata.IsArray()) {
+      ASSERT(Array::Cast(metadata).raw() != Object::empty_array().raw());
+      field.set_value(Array::Cast(metadata));
+    }
+  }
+  return metadata.raw();
+}
+
+
 const char* Namespace::ToCString() const {
   const char* kFormat = "Namespace for library '%s'";
   const Library& lib = Library::Handle(library());