Only use pending navigation params for browser-initiated navigations.

third_party/WebKit/public/web/WebFrameClient.h

 /*
  * Copyright (C) 2011, 2012 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 328 matching lines @@
     // WebHistoryCommitType is the commit type that would have been used had the
     // load succeeded.
     virtual void didFailLoad(WebLocalFrame*, const WebURLError&, WebHistoryCommitType) { }
 
     // The frame's document and all of its subresources succeeded to load.
     virtual void didFinishLoad(WebLocalFrame*) { }
 
     // The navigation resulted in no change to the documents within the page.
     // For example, the navigation may have just resulted in scrolling to a
     // named anchor or a PopState event may have been dispatched.
-    virtual void didNavigateWithinPage(WebLocalFrame*, const WebHistoryItem&, WebHistoryCommitType) { }
+    virtual void didNavigateWithinPage(WebLocalFrame*, const WebHistoryItem&, WebHistoryCommitType, bool contentInitiated) { }
 
     // Called upon update to scroll position, document state, and other
     // non-navigational events related to the data held by WebHistoryItem.
     // WARNING: This method may be called very frequently.
     virtual void didUpdateCurrentHistoryItem() { }
 
     // The frame's manifest has changed.
     virtual void didChangeManifest() { }
 
     // The frame's theme color has changed.
@@ skipping 358 matching lines @@
     // Mojo ----------------------------------------------------------------
     virtual ServiceRegistry* serviceRegistry() { return nullptr; }
 
 protected:
     virtual ~WebFrameClient() { }
 };
 
 } // namespace blink
 
 #endif