Always send a fail or finish notification for each navigation.

third_party/WebKit/Source/core/loader/DocumentLoader.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 256 matching lines @@
   Member<ContentSecurityPolicy> m_contentSecurityPolicy;
   ClientHintsPreferences m_clientHintsPreferences;
   InitialScrollState m_initialScrollState;
 
   bool m_wasBlockedAfterXFrameOptionsOrCSP;
 
   enum State {
     NotStarted,
     Provisional,
     Committed,
-    MainResourceDone,

[Nate Chapin, 2016/12/12 21:40:37]

This state isn't actually used for anything, it's functionally equivalent to
Committed.

     SentDidFinishLoad
   };
   State m_state;
 
   // Used to protect against reentrancy into dataReceived().
   bool m_inDataReceived;
   RefPtr<SharedBuffer> m_dataBuffer;
 };
 
 DECLARE_WEAK_IDENTIFIER_MAP(DocumentLoader);
 
 }  // namespace blink
 
 #endif  // DocumentLoader_h