Add DidSaveScrollOrScaleState flag to prevent restoreScrollPositionAndViewState restore from default

third_party/WebKit/Source/core/frame/FrameView.h

Index: third_party/WebKit/Source/core/frame/FrameView.h
diff --git a/third_party/WebKit/Source/core/frame/FrameView.h b/third_party/WebKit/Source/core/frame/FrameView.h
index 983b32826d2e339f7db46b4df500c98be43a6ec5..0e294a824747f5d23ff398f4e975459e24af54ce 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.h
+++ b/third_party/WebKit/Source/core/frame/FrameView.h
@@ -1014,6 +1014,8 @@ class CORE_EXPORT FrameView final
 
   PaintController* paintController() { return m_paintController.get(); }
 
+  void setScrollFromNavigation();

[majidvp, 2017/01/24 21:53:52]

In the frameview case, the scroll position is 
reset after size changes (e.g., content size or frame size).

This is not necessarily happening after navigation 
so the function name seem a bit inappropriate. Maybe
setScrollAfter[Scroll?]SizeChange ?

+
   LayoutSize m_size;
 
   typedef HashSet<RefPtr<LayoutEmbeddedObject>> EmbeddedObjectSet;