mac: Fix bookmark drag and drop.

chrome/browser/ui/cocoa/bookmarks/bookmark_button.h

 // Copyright (c) 2011 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 <Cocoa/Cocoa.h>
 #include <vector>
 #import "chrome/browser/ui/cocoa/draggable_button.h"
 #import "chrome/browser/ui/cocoa/themed_window.h"
 #include "ui/base/window_open_disposition.h"
 
 @class BookmarkBarFolderController;
 @class BookmarkButton;
 @class BrowserWindowController;
 class Profile;
 
 namespace bookmarks {
 class BookmarkModel;
 class BookmarkNode;
 }
 
 // Protocol for a BookmarkButton's delegate, responsible for doing
 // things on behalf of a bookmark button.
 @protocol BookmarkButtonDelegate
 
-// Fill the given pasteboard with appropriate data when the given button is
-// dragged. Since the delegate has no way of providing pasteboard data later,
-// all data must actually be put into the pasteboard and not merely promised.
-- (void)fillPasteboard:(NSPasteboard*)pboard
-       forDragOfButton:(BookmarkButton*)button;
+// Returns a pasteboard item that has all bookmark information.
+- (NSPasteboardItem*)pasteboardItemForDragOfButton:(BookmarkButton*)button;
 
 // Bookmark buttons pass mouseEntered: and mouseExited: events to
 // their delegate.  This allows the delegate to decide (for example)
 // which one, if any, should perform a hover-open.
 - (void)mouseEnteredButton:(id)button event:(NSEvent*)event;
 - (void)mouseExitedButton:(id)button event:(NSEvent*)event;
 
 // Returns YES if a drag operation should lock the fullscreen overlay bar
 // visibility before starting.  For example, dragging a bookmark button should
 // not lock the overlay if the bookmark bar is currently showing in detached
 // mode on the NTP.
 - (BOOL)dragShouldLockBarVisibility;
 
 // Returns the top-level window for this button.
 - (NSWindow*)browserWindow;
 
 // Returns YES if the bookmark button can be dragged to the trash, NO otherwise.
 - (BOOL)canDragBookmarkButtonToTrash:(BookmarkButton*)button;
 
 // This is called after the user has dropped the bookmark button on the trash.
 // The delegate can use this event to delete the bookmark.
 - (void)didDragBookmarkToTrash:(BookmarkButton*)button;
 
 // This is called after the drag has finished, for any reason.
 // We particularly need this so we can hide bookmark folder menus and stop
 // doing that hover thing.
 - (void)bookmarkDragDidEnd:(BookmarkButton*)button
                  operation:(NSDragOperation)operation;
 
+@optional
+// Called when a pasteboard drag is about to begin.
+- (void)willBeginPasteboardDrag;
+
 @end
 
 
 // Protocol to be implemented by controllers that logically own
 // bookmark buttons.  The controller may be either an NSViewController
 // or NSWindowController.  The BookmarkButton doesn't use this
 // protocol directly; it is used when BookmarkButton controllers talk
 // to each other.
 //
 // Other than the top level owner (the bookmark bar), all bookmark
@@ skipping 177 matching lines @@
 + (BookmarkButton*)draggedButton;
 
 
 @end  // @interface BookmarkButton
 
 
 @interface BookmarkButton(TestingAPI)
 - (void)beginDrag:(NSEvent*)event;
 @end