[Offline pages] Resetting offline page metadata store if initial load fails

components/offline_pages/offline_page_metadata_store.h

Index: components/offline_pages/offline_page_metadata_store.h
diff --git a/components/offline_pages/offline_page_metadata_store.h b/components/offline_pages/offline_page_metadata_store.h
index 26314804bdce08b2df6e0ad0280aee4937a3fb73..c1ee45d017941f44c7ad3525ed56e14d1be14cf2 100644
--- a/components/offline_pages/offline_page_metadata_store.h
+++ b/components/offline_pages/offline_page_metadata_store.h
@@ -26,20 +26,8 @@ typedef StoreUpdateResult<OfflinePageItem> OfflinePagesUpdateResult;
 // issue multiple asynchronous operations in parallel.
 class OfflinePageMetadataStore {
  public:
-  // This enum is used in an UMA histogram. Hence the entries here shouldn't
-  // be deleted or re-ordered and new ones should be added to the end.
-  enum LoadStatus {
-    LOAD_SUCCEEDED,
-    STORE_INIT_FAILED,
-    STORE_LOAD_FAILED,
-    DATA_PARSING_FAILED,
-
-    // NOTE: always keep this entry at the end.
-    LOAD_STATUS_COUNT
-  };
-
-  typedef base::Callback<void(LoadStatus, const std::vector<OfflinePageItem>&)>
-      LoadCallback;
+  typedef base::Callback<void(StoreState, const std::vector<OfflinePageItem>&)>
+      GetOfflinePagesCallback;
   typedef base::Callback<void(ItemActionStatus)> AddCallback;
   typedef base::Callback<void(std::unique_ptr<OfflinePagesUpdateResult>)>
       UpdateCallback;
@@ -49,7 +37,7 @@ class OfflinePageMetadataStore {
   virtual ~OfflinePageMetadataStore();
 
   // Get all of the offline pages from the store.
-  virtual void GetOfflinePages(const LoadCallback& callback) = 0;
+  virtual void GetOfflinePages(const GetOfflinePagesCallback& callback) = 0;
 
   // Asynchronously adds an offline page item metadata to the store.
   virtual void AddOfflinePage(const OfflinePageItem& offline_page,