Add DCHECK that Reload should never be called with ReloadType::NONE

content/browser/frame_host/navigation_controller_impl.cc

 // Copyright 2013 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.
 
 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  *     (http://www.torchmobile.com/)
  *
@@ skipping 279 matching lines @@
   // At this point, the |entries| is full of empty scoped_ptrs, so it can be
   // cleared out safely.
   entries->clear();
 
   // And finish the restore.
   FinishRestore(selected_navigation, type);
 }
 
 void NavigationControllerImpl::Reload(ReloadType reload_type,
                                       bool check_for_repost) {
+  DCHECK_NE(reload_type, ReloadType::NONE);

[Charlie Reis, 2017/03/10 17:41:05]

Minor nit: Swap order of arguments.  (DCHECK macros are normally "expected,
actual", which can affect how a failure message is phrased.)

[liaoyuke, 2017/03/10 18:00:14]

Done.

+
   if (transient_entry_index_ != -1) {
     // If an interstitial is showing, treat a reload as a navigation to the
     // transient entry's URL.
     NavigationEntryImpl* transient_entry = GetTransientEntry();
     if (!transient_entry)
       return;
     LoadURL(transient_entry->GetURL(),
             Referrer(),
             ui::PAGE_TRANSITION_RELOAD,
             transient_entry->extra_headers());
@@ skipping 1840 matching lines @@
     }
   }
 }
 
 void NavigationControllerImpl::SetGetTimestampCallbackForTest(
     const base::Callback<base::Time()>& get_timestamp_callback) {
   get_timestamp_callback_ = get_timestamp_callback;
 }
 
 }  // namespace content