Fix race condition if a pulsing bookmark button is deleted while the bookmark bubble controller is …

chrome/browser/ui/cocoa/bookmarks/bookmark_model_observer_for_cocoa.mm

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/ui/cocoa/bookmarks/bookmark_model_observer_for_cocoa.h"
 
 BookmarkModelObserverForCocoa::BookmarkModelObserverForCocoa(
-    const BookmarkNode* node,
     BookmarkModel* model,
-    NSObject* object,
-    SEL selector) {
+    ChangeCallback callback) {
   DCHECK(model);
-  node_ = node;
+  callback_.reset(Block_copy(callback));
   model_ = model;
-  object_ = object;
-  selector_ = selector;
   model_->AddObserver(this);
 }
 
 BookmarkModelObserverForCocoa::~BookmarkModelObserverForCocoa() {
   model_->RemoveObserver(this);
 }
 
+void BookmarkModelObserverForCocoa::StartObservingNode(
+    const BookmarkNode* node) {
+  nodes_.insert(node);
+}
+
+void BookmarkModelObserverForCocoa::StopObservingNode(
+    const BookmarkNode* node) {
+  nodes_.erase(node);
+}
+
 void BookmarkModelObserverForCocoa::BookmarkModelBeingDeleted(
     BookmarkModel* model) {
-  Notify();
+  Notify(YES);
 }
 
 void BookmarkModelObserverForCocoa::BookmarkNodeMoved(
     BookmarkModel* model,
     const BookmarkNode* old_parent,
     int old_index,
     const BookmarkNode* new_parent,
     int new_index) {
   // Editors often have a tree of parents, so movement of folders
   // must cause a cancel.
-  Notify();
+  Notify(NO);
 }
 
 void BookmarkModelObserverForCocoa::BookmarkNodeRemoved(
     BookmarkModel* model,
     const BookmarkNode* parent,
     int old_index,
     const BookmarkNode* node) {
   // See comment in BookmarkNodeMoved.
-  Notify();
+  Notify(YES);
 }
 
 void BookmarkModelObserverForCocoa::BookmarkAllNodesRemoved(
     BookmarkModel* model) {
-  Notify();
+  Notify(YES);
 }
 
 void BookmarkModelObserverForCocoa::BookmarkNodeChanged(
     BookmarkModel* model,
     const BookmarkNode* node) {
-  if ((node_ == node) || (!node_))
-    Notify();
+  if (!nodes_.size() || nodes_.find(node) != nodes_.end())
+    Notify(NO);
 }
 
-void BookmarkModelObserverForCocoa::ExtensiveBookmarkChangesBeginning(
-    BookmarkModel* model) {
-  // Be conservative.
-  Notify();
+void BookmarkModelObserverForCocoa::Notify(BOOL deleted) {
+  callback_.get()(deleted);
 }
-
-void BookmarkModelObserverForCocoa::Notify() {
-  [object_ performSelector:selector_ withObject:nil];
-}