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

chrome/browser/ui/cocoa/bookmarks/bookmark_name_folder_controller.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.
 
 #import "chrome/browser/ui/cocoa/bookmarks/bookmark_name_folder_controller.h"
 
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "chrome/browser/bookmarks/bookmark_model_factory.h"
@@ skipping 62 matching lines @@
   [nameField_ setStringValue:initialName_.get()];
   [[nameField_ cell] setUsesSingleLineMode:YES];
 
   [okButton_ setTitle:l10n_util::GetNSStringWithFixup(node_ ? IDS_SAVE :
                                                               IDS_ADD)];
 }
 
 - (void)runAsModalSheet {
   // Ping me when things change out from under us.
   observer_.reset(new BookmarkModelObserverForCocoa(
-                    node_, BookmarkModelFactory::GetForProfile(profile_),
-                    self,
-                    @selector(cancel:)));
+                    BookmarkModelFactory::GetForProfile(profile_),
+                    ^(BOOL nodeWasDeleted) {
+                        [self cancel:nil];
+                    }));
+  observer_->StartObservingNode(node_);
   [NSApp beginSheet:[self window]
      modalForWindow:parentWindow_
       modalDelegate:self
      didEndSelector:@selector(didEndSheet:returnCode:contextInfo:)
         contextInfo:nil];
 }
 
 - (IBAction)cancel:(id)sender {
   [NSApp endSheet:[self window]];
 }
@@ skipping 25 matching lines @@
 
 - (void)setFolderName:(NSString*)name {
   [nameField_ setStringValue:name];
 }
 
 - (NSButton*)okButton {
   return okButton_;
 }
 
 @end  // BookmarkNameFolderController