Supporting undoing bookmark deletion without creating new ID.

components/bookmarks/browser/bookmark_model.h

Index: components/bookmarks/browser/bookmark_model.h
diff --git a/components/bookmarks/browser/bookmark_model.h b/components/bookmarks/browser/bookmark_model.h
index 27837703d0adc6719ef330fb483cd6afe1d1bcb7..7e17c1857479531a1f001c37e71698b950c1f432 100644
--- a/components/bookmarks/browser/bookmark_model.h
+++ b/components/bookmarks/browser/bookmark_model.h
@@ -20,6 +20,7 @@
 #include "base/synchronization/waitable_event.h"
 #include "components/bookmarks/browser/bookmark_client.h"
 #include "components/bookmarks/browser/bookmark_node.h"
+#include "components/bookmarks/browser/bookmark_undo_provider.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "ui/gfx/image/image.h"
 #include "url/gurl.h"
@@ -47,6 +48,7 @@ class BookmarkIndex;
 class BookmarkLoadDetails;
 class BookmarkModelObserver;
 class BookmarkStorage;
+class BookmarkUndoDelegate;
 class ScopedGroupBookmarkActions;
 class TestBookmarkClient;
 struct BookmarkMatch;
@@ -61,7 +63,8 @@ struct BookmarkMatch;
 //
 // You should NOT directly create a BookmarkModel, instead go through the
 // BookmarkModelFactory.
-class BookmarkModel : public KeyedService {
+class BookmarkModel : public BookmarkUndoProvider,
+                      public KeyedService {
  public:
   struct URLAndTitle {
     GURL url;
@@ -308,6 +311,8 @@ class BookmarkModel : public KeyedService {
   // Returns the client used by this BookmarkModel.
   BookmarkClient* client() const { return client_; }
 
+  void SetUndoDelegate(BookmarkUndoDelegate* undo_delegate);
+
  private:
   friend class BookmarkCodecTest;
   friend class BookmarkModelFaviconTest;
@@ -323,6 +328,14 @@ class BookmarkModel : public KeyedService {
     }
   };
 
+  // BookmarkUndoProvider:
+  void RestoreRemovedNode(const BookmarkNode* parent,
+                          int index,
+                          scoped_ptr<BookmarkNode> node) override;
+
+  // Notifies the observers for adding every descedent of |node|.
+  void NotifyNodeAddedForAllDescendents(const BookmarkNode* node);
+
   // Implementation of IsBookmarked. Before calling this the caller must obtain
   // a lock on |url_lock_|.
   bool IsBookmarkedNoLock(const GURL& url);
@@ -405,6 +418,8 @@ class BookmarkModel : public KeyedService {
   scoped_ptr<BookmarkLoadDetails> CreateLoadDetails(
       const std::string& accept_languages);
 
+  BookmarkUndoDelegate* undo_delegate() const;
+
   BookmarkClient* const client_;
 
   // Whether the initial set of data has been loaded.
@@ -449,6 +464,9 @@ class BookmarkModel : public KeyedService {
 
   std::set<std::string> non_cloned_keys_;
 
+  BookmarkUndoDelegate* undo_delegate_;
+  scoped_ptr<BookmarkUndoDelegate> empty_undo_delegate_;
+
   DISALLOW_COPY_AND_ASSIGN(BookmarkModel);
 };