[MD History] Fix deletion in heavily scrolled list.

chrome/browser/ui/webui/browsing_history_handler.cc

 // Copyright 2015 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/webui/browsing_history_handler.h"
 
 #include <stddef.h>
 
 #include <set>
 #include <utility>
@@ skipping 992 matching lines @@
     history::HistoryService* history_service,
     bool all_history,
     bool expired,
     const history::URLRows& deleted_rows,
     const std::set<GURL>& favicon_urls) {
   if (all_history || DeletionsDiffer(deleted_rows, urls_to_be_deleted_))
     web_ui()->CallJavascriptFunctionUnsafe("historyDeleted");
 }
 
 void BrowsingHistoryHandler::OnWebHistoryDeleted() {
-  web_ui()->CallJavascriptFunctionUnsafe("historyDeleted");
+  if (!has_pending_delete_request_)

[msramek, 2016/11/07 15:45:20]

It's possible that OnWebHistoryDeleted() was called for a request not coming
from this page (e.g. from CBD or another instance of the history page). In that
case, we should reload to display the effects of that deletion.

It's just a corner case, and it requires further changes to
OnWebHistoryDeleted(), so I'm not asking you to fix it now, but can you please
document that we know about it? Someone will look at this code later and will
wonder why can we assume that the web history deletion comes from this handler.

+    web_ui()->CallJavascriptFunctionUnsafe("historyDeleted");
 }