Fix inheritance in Reading List

components/reading_list/ios/reading_list_store_delegate.h

Index: components/reading_list/ios/reading_list_store_delegate.h
diff --git a/components/reading_list/ios/reading_list_store_delegate.h b/components/reading_list/ios/reading_list_store_delegate.h
index a50e6d6b6782f1f76be2374423e6cfe94de353ba..d95100c353fa16e7cfbf14020782ed9075d01750 100644
--- a/components/reading_list/ios/reading_list_store_delegate.h
+++ b/components/reading_list/ios/reading_list_store_delegate.h
@@ -14,9 +14,6 @@ class ReadingListEntry;
 // The delegate to handle callbacks from the ReadingListStore.
 class ReadingListStoreDelegate {
  public:
-  ReadingListStoreDelegate() {}
-  virtual ~ReadingListStoreDelegate() {}
-
   using ReadingListEntries = std::map<GURL, ReadingListEntry>;
   // These three methods handle callbacks from a ReadingListStore.
   // This method is called when the local store is loaded. |entries| contains
@@ -36,6 +33,11 @@ class ReadingListStoreDelegate {
 
   // Called to remove an entry to the model.
   virtual void SyncRemoveEntry(const GURL& url) = 0;
+
+ protected:
+  ReadingListStoreDelegate() {}
+  virtual ~ReadingListStoreDelegate() {}
+
  private:
   DISALLOW_COPY_AND_ASSIGN(ReadingListStoreDelegate);
 };