Add DidSaveScrollOrScaleState flag to prevent restoreScrollPositionAndViewState restore from default

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

 /*
  * Copyright (C) 2006, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2012 Research In Motion Limited. 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.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 81 matching lines @@
   }
   long long documentSequenceNumber() const { return m_documentSequenceNumber; }
 
   void setScrollRestorationType(HistoryScrollRestorationType type) {
     m_scrollRestorationType = type;
   }
   HistoryScrollRestorationType scrollRestorationType() {
     return m_scrollRestorationType;
   }
 
+  void setDidSaveScrollState(bool hasSaveScrollState) {
+    m_didSaveScrollState = hasSaveScrollState;
+  }
+
+  bool didSaveScrollState() const { return m_didSaveScrollState; }
+
   void setFormInfoFromRequest(const ResourceRequest&);
   void setFormData(PassRefPtr<EncodedFormData>);
   void setFormContentType(const AtomicString&);
 
   bool isCurrentDocument(Document*) const;
 
   DECLARE_TRACE();
 
  private:
   HistoryItem();
@@ skipping 23 matching lines @@
   // position should be restored when it is loaded during history traversal.
   HistoryScrollRestorationType m_scrollRestorationType;
 
   // Support for HTML5 History
   RefPtr<SerializedScriptValue> m_stateObject;
 
   // info used to repost form data
   RefPtr<EncodedFormData> m_formData;
   AtomicString m_formContentType;
 
+  bool m_didSaveScrollState;

[majidvp, 2017/02/14 20:42:17]

nit: maybe move this next to scroll state related fields.

+
 };  // class HistoryItem
 
 }  // namespace blink
 
 #endif  // HISTORYITEM_H