[Offline pages] Detecting missing offline copy

components/offline_pages/offline_page_model.h

Index: components/offline_pages/offline_page_model.h
diff --git a/components/offline_pages/offline_page_model.h b/components/offline_pages/offline_page_model.h
index 648a0f4002758696ef7cafbc70a3291bf15c0b16..7831d3bb25f449eeb44778ade1cc1a636e588cc4 100644
--- a/components/offline_pages/offline_page_model.h
+++ b/components/offline_pages/offline_page_model.h
@@ -97,6 +97,8 @@ class OfflinePageModel : public KeyedService,
    public:
     // Invoked when the model has finished loading.
     virtual void OfflinePageModelLoaded(OfflinePageModel* model) = 0;
+    // Invoked when an offline copy related to |bookmark_id| was deleted.
+    virtual void OfflinePageDeleted(int64 bookmark_id) = 0;
 
    protected:
     virtual ~Observer() {}
@@ -156,10 +158,13 @@ class OfflinePageModel : public KeyedService,
   // is returned if not found.
   const OfflinePageItem* GetPageByBookmarkId(int64 bookmark_id) const;
 
-  // Returns an offline page that is stored as |offline_url|. nullptr is
+  // Returns an offline page that is stored as |offline_url|. A nullptr is
   // returned if not found.
   const OfflinePageItem* GetPageByOfflineURL(const GURL& offline_url) const;
 
+  // Checks that all of the offline pages have corresponding offline copies.

[jianli, 2015/10/14 22:30:23]

Can you be a bit more specific in the comment? I think offline pages already
mean to save offline copies and we should try to avoid referring to offline copy
here since it is more UI term. Can we just say "Checks all offline pages to make
sure saved files are still present, i.e. not being deleted by external
programs"?

Could you please also comment the consequence of this, like metadata being
removed and OfflinePageDeleted being fired? 

[fgorski, 2015/10/15 19:12:29]

I disagree. See line 36 in this file.
Done.

+  void CheckForExternalFileDeletion();
+
   // Methods for testing only:
   OfflinePageMetadataStore* GetStoreForTesting();
 
@@ -211,6 +216,10 @@ class OfflinePageModel : public KeyedService,
   void OnUpdateOfflinePageDone(const OfflinePageItem& offline_page_item,
                                bool success);
 
+  // Callback for check if offline pages missing offline files.
+  void OnListPagesMissingArchiveFileDone(
+      const std::vector<int64>* pages_missing_archive_file);
+
   // Persistent store for offline page metadata.
   scoped_ptr<OfflinePageMetadataStore> store_;