[Offline Pages] Remove load state from public OfflinePageModel API.

components/offline_pages/core/stub_offline_page_model.cc

Index: components/offline_pages/core/stub_offline_page_model.cc
diff --git a/components/offline_pages/core/stub_offline_page_model.cc b/components/offline_pages/core/stub_offline_page_model.cc
index dcc69c4b4d85018029e9efa71d5da8290f6cd1c4..55c359af9a437396be20b33f69a91973e68d5003 100644
--- a/components/offline_pages/core/stub_offline_page_model.cc
+++ b/components/offline_pages/core/stub_offline_page_model.cc
@@ -49,9 +49,6 @@ void StubOfflinePageModel::GetPagesByURL(
 ClientPolicyController* StubOfflinePageModel::GetPolicyController() {
   return &policy_controller_;
 }
-bool StubOfflinePageModel::is_loaded() const {
-  return true;
-}
 OfflineEventLogger* StubOfflinePageModel::GetLogger() {
   return nullptr;
 }