Move ReadingList model to components/reading_list/core

components/reading_list/ios/proto/BUILD.gn

Index: components/reading_list/ios/proto/BUILD.gn
diff --git a/components/reading_list/ios/proto/BUILD.gn b/components/reading_list/ios/proto/BUILD.gn
deleted file mode 100644
index 927a5eea83e167675b2cb6fee3186b0fced0cffa..0000000000000000000000000000000000000000
--- a/components/reading_list/ios/proto/BUILD.gn
+++ /dev/null
@@ -1,14 +0,0 @@
-# Copyright 2016 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-import("//third_party/protobuf/proto_library.gni")
-
-proto_library("proto") {
-  sources = [
-    "reading_list.proto",
-  ]
-  deps = [
-    "//components/sync/protocol",
-  ]
-}