[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..24acf3c1d4c530bd20f5e5e0e6273040bceaca62 100644
--- a/components/offline_pages/offline_page_model.h
+++ b/components/offline_pages/offline_page_model.h
@@ -97,6 +97,7 @@ class OfflinePageModel : public KeyedService,
    public:
     // Invoked when the model has finished loading.
     virtual void OfflinePageModelLoaded(OfflinePageModel* model) = 0;
+    virtual void OfflinePageDeleted(int64 bookmark_id) = 0;

[jianli, 2015/10/13 00:17:54]

nit: please add comment

[fgorski, 2015/10/13 17:39:58]

Done.

 
    protected:
     virtual ~Observer() {}
@@ -156,10 +157,13 @@ 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.
+  void CheckMetadataConsistency();

[jianli, 2015/10/13 00:17:54]

Since we're only checking if the file is still there, the name to indicate
checking all metadata seems to be too broad. How about
CheckForExternalFileDeletion?

[fgorski, 2015/10/13 17:39:58]

I am ok with making that change in the model now, but I would rather not expose
such intimate knowledge of offline pages to the UI layer. I am only ok to make
such change on the backend side.

+
   // Methods for testing only:
   OfflinePageMetadataStore* GetStoreForTesting();
 
@@ -211,6 +215,10 @@ class OfflinePageModel : public KeyedService,
   void OnUpdateOfflinePageDone(const OfflinePageItem& offline_page_item,
                                bool success);
 
+  // Callback for check if offline pages missing offline files.
+  void OnListPagesMissingOfflineCopy(

[jianli, 2015/10/13 00:17:54]

It would be consistent with the naming "archive file" we use here. How about
OnValidateArchiveFilesDone?

[fgorski, 2015/10/13 17:39:58]

Done.

+      const std::vector<int64>* pages_missing_offline_copy);
+
   // Persistent store for offline page metadata.
   scoped_ptr<OfflinePageMetadataStore> store_;