Convert String and List to abstract classes.

runtime/vm/object_store.h

Index: runtime/vm/object_store.h
diff --git a/runtime/vm/object_store.h b/runtime/vm/object_store.h
index c0f6797f302651c805f642c3935aa77534ae8a97..f0f382d88ce6d869e0848663d6cd7a9898658daf 100644
--- a/runtime/vm/object_store.h
+++ b/runtime/vm/object_store.h
@@ -102,9 +102,9 @@ class ObjectStore {
   RawClass* bigint_class() const { return bigint_class_; }
   void set_bigint_class(const Class& value) { bigint_class_ = value.raw(); }
 
-  RawType* string_interface() const { return string_interface_; }
-  void set_string_interface(const Type& value) {
-    string_interface_ = value.raw();
+  RawType* string_type() const { return string_type_; }
+  void set_string_type(const Type& value) {
+    string_type_ = value.raw();
   }
 
   RawClass* one_byte_string_class() const { return one_byte_string_class_; }
@@ -149,9 +149,9 @@ class ObjectStore {
   RawClass* bool_class() const { return bool_class_; }
   void set_bool_class(const Class& value) { bool_class_ = value.raw(); }
 
-  RawType* list_interface() const { return list_interface_; }
-  void set_list_interface(const Type& value) {
-    list_interface_ = value.raw();
+  RawType* list_type() const { return list_type_; }
+  void set_list_type(const Type& value) {
+    list_type_ = value.raw();
   }
 
   RawClass* array_class() const { return array_class_; }
@@ -489,7 +489,7 @@ class ObjectStore {
   RawClass* bigint_class_;
   RawClass* double_class_;
   RawType* double_type_;
-  RawType* string_interface_;
+  RawType* string_type_;
   RawClass* one_byte_string_class_;
   RawClass* two_byte_string_class_;
   RawClass* four_byte_string_class_;
@@ -498,7 +498,7 @@ class ObjectStore {
   RawClass* external_four_byte_string_class_;
   RawType* bool_type_;
   RawClass* bool_class_;
-  RawType* list_interface_;
+  RawType* list_type_;
   RawClass* array_class_;
   RawClass* immutable_array_class_;
   RawClass* growable_object_array_class_;