[MD Bookmarks] Add undo/redo functionality to MD Bookmarks.

chrome/browser/bookmarks/bookmark_model_factory.cc

 // 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/bookmarks/bookmark_model_factory.h"
 
 #include "base/command_line.h"
 #include "base/deferred_sequenced_task_runner.h"
 #include "base/memory/ptr_util.h"
 #include "base/memory/singleton.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "chrome/browser/bookmarks/chrome_bookmark_client.h"
 #include "chrome/browser/bookmarks/managed_bookmark_service_factory.h"
 #include "chrome/browser/bookmarks/startup_task_runner_service_factory.h"
 #include "chrome/browser/profiles/incognito_helpers.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/webui/md_bookmarks/md_bookmarks_ui.h"
 #include "chrome/browser/undo/bookmark_undo_service_factory.h"
 #include "chrome/common/chrome_switches.h"
 #include "components/bookmarks/browser/bookmark_model.h"
 #include "components/bookmarks/browser/bookmark_utils.h"
 #include "components/bookmarks/browser/startup_task_runner_service.h"
 #include "components/keyed_service/content/browser_context_dependency_manager.h"
 #include "components/prefs/pref_service.h"
 #include "components/undo/bookmark_undo_service.h"
 #include "content/public/browser/browser_thread.h"
 
@@ skipping 38 matching lines @@
           profile, ManagedBookmarkServiceFactory::GetForProfile(profile)));
   bookmark_model->Load(profile->GetPrefs(), profile->GetPath(),
                        StartupTaskRunnerServiceFactory::GetForProfile(profile)
                            ->GetBookmarkTaskRunner(),
                        content::BrowserThread::GetTaskRunnerForThread(
                            content::BrowserThread::UI));
   bool register_bookmark_undo_service_as_observer = true;
 #if !defined(OS_ANDROID)
   register_bookmark_undo_service_as_observer =
       base::CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kEnableBookmarkUndo);
+          switches::kEnableBookmarkUndo) ||
+      MdBookmarksUI::IsEnabled();

[sky, 2017/05/24 16:57:16]

Where do we make use of the undo in non-android? For example,
chrome/browser/ui/bookmarks/bookmark_context_menu_controller.cc doesn't look at
this conditional. How about a single function for testing if undo is enabled so
it's easier to update all places?

[calamity, 2017/05/25 08:54:02]

It's behind a flag for the bookmarks bar context menu, but that's all I think.
I've made the BookmarkUndoService::IsEnabled() function but I don't think I
should hook the Bookmarks Bar context menu up to that function because it's a
product change and should probably go through a PM/UX once-over first.

I think we'll aim to remove the kEnableBookmarkUndo flag one way or the other.
We'll either enable it for the context menu always, or remove the context menu
code and have it locked to MD Bookmarks.

[sky, 2017/05/25 18:09:06]

If you don't enable undo in the menu how is it possible to use undo?

Given your in a different timezone I'm going to approve this assuming you have
it wired up somewhere.

 #endif  // !defined(OS_ANDROID)
   if (register_bookmark_undo_service_as_observer)
     BookmarkUndoServiceFactory::GetForProfile(profile)->Start(bookmark_model);
 
   return bookmark_model;
 }
 
 void BookmarkModelFactory::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* registry) {
   bookmarks::RegisterProfilePrefs(registry);
 }
 
 content::BrowserContext* BookmarkModelFactory::GetBrowserContextToUse(
     content::BrowserContext* context) const {
   return chrome::GetBrowserContextRedirectedInIncognito(context);
 }
 
 bool BookmarkModelFactory::ServiceIsNULLWhileTesting() const {
   return true;
 }