Add Store+Sync to reading list.

ios/chrome/browser/reading_list/reading_list_store_delegate.h

Index: ios/chrome/browser/reading_list/reading_list_store_delegate.h
diff --git a/ios/chrome/browser/reading_list/reading_list_store_delegate.h b/ios/chrome/browser/reading_list/reading_list_store_delegate.h
new file mode 100644
index 0000000000000000000000000000000000000000..99170341338f216eec0777676b2fecdc5b44031a
--- /dev/null
+++ b/ios/chrome/browser/reading_list/reading_list_store_delegate.h
@@ -0,0 +1,34 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef IOS_CHROME_BROWSER_READING_LIST_READING_LIST_STORE_DELEGATE_H_
+#define IOS_CHROME_BROWSER_READING_LIST_READING_LIST_STORE_DELEGATE_H_
+
+class ReadingListEntry;
+
+// The delegate to handle callbacks from the ReadingListStore.
+class ReadingListStoreDelegate {
+ public:
+  // These three mathods handle callbacks from a ReadingListStore.
+  virtual void StoreLoaded(std::unique_ptr<ReadingListEntries> unread,
+                           std::unique_ptr<ReadingListEntries> read) = 0;
+  // Handle sync events.
+  // Called to add a new entry to the model.
+  // |entry| must not already exist in the model.
+  virtual void SyncAddEntry(std::unique_ptr<ReadingListEntry> entry,
+                            bool read) = 0;
+
+  // Called to merge a sync entry with a local entry in the model.
+  // A local entry with the same URL must exist in the local store and have an
+  // older UpdateTime.
+  // Return a pointer to the merged entry.
+  virtual ReadingListEntry* SyncMergeEntry(
+      std::unique_ptr<ReadingListEntry> entry,
+      bool read) = 0;
+
+  // Called to remove an entry to the model.
+  virtual void SyncRemoveEntry(const GURL& url) = 0;
+};
+
+#endif  // IOS_CHROME_BROWSER_READING_LIST_READING_LIST_STORE_DELEGATE_H_