3 files changed, 27 insertions, 0 deletions
diff --git a/chrome/browser/bookmarks/bookmark_model.cc b/chrome/browser/bookmarks/bookmark_model.cc
index 434fde0..5385810 100644
--- a/chrome/browser/bookmarks/bookmark_model.cc
+++ b/chrome/browser/bookmarks/bookmark_model.cc
@@ -609,6 +609,16 @@ void BookmarkModel::RemoveAndDeleteNode(BookmarkNode* delete_me) {
       Details<history::URLsStarredDetails>(&details));
 }
 
+void BookmarkModel::BeginImportMode() {
+  FOR_EACH_OBSERVER(BookmarkModelObserver, observers_,
+                    BookmarkImportBeginning(this));
+}
+
+void BookmarkModel::EndImportMode() {
+  FOR_EACH_OBSERVER(BookmarkModelObserver, observers_,
+                    BookmarkImportEnding(this));
+}
+
 BookmarkNode* BookmarkModel::AddNode(BookmarkNode* parent,
                                      int index,
                                      BookmarkNode* node,
diff --git a/chrome/browser/bookmarks/bookmark_model.h b/chrome/browser/bookmarks/bookmark_model.h
index fcea7c7..1ffdcbe 100644
--- a/chrome/browser/bookmarks/bookmark_model.h
+++ b/chrome/browser/bookmarks/bookmark_model.h
@@ -205,6 +205,12 @@ class BookmarkModel : public NotificationObserver, public BookmarkService {
     observers_.RemoveObserver(observer);
   }
 
+  // Notify the observes that an import is about to happen, so they can
+  // delay any expensive UI updates until it is finished.
+  void BeginImportMode();
+  void EndImportMode();
+
+
   // Unstars or deletes the specified entry. Removing a group entry recursively
   // unstars all nodes. Observers are notified immediately.
   void Remove(const BookmarkNode* parent, int index);
diff --git a/chrome/browser/bookmarks/bookmark_model_observer.h b/chrome/browser/bookmarks/bookmark_model_observer.h
index e850cb3..2136475 100644
--- a/chrome/browser/bookmarks/bookmark_model_observer.h
+++ b/chrome/browser/bookmarks/bookmark_model_observer.h
@@ -52,6 +52,17 @@ class BookmarkModelObserver {
   virtual void BookmarkNodeChildrenReordered(BookmarkModel* model,
                                              const BookmarkNode* node) = 0;
 
+  // Invoked before a batch import begins.  This tells UI intensive observers
+  // to wait until the updates finish to update themselves.
+  // These methods should only be used for imports. Observers should still
+  // respond to BookmarkNodeRemoved immediately, to avoid holding onto
+  // stale node pointers.
+  virtual void BookmarkImportBeginning(BookmarkModel* model) {}
+
+  // Invoked after a batch import finishes.  This tells observers to update
+  // themselves if they were waiting for the update to finish.
+  virtual void BookmarkImportEnding(BookmarkModel* model) {}
+
  protected:
   virtual ~BookmarkModelObserver() {}
 };