Scroll offset pinning and content size notifications were only used for the Mac overlay navigation …

content/renderer/render_view_impl.h

Index: content/renderer/render_view_impl.h
diff --git a/content/renderer/render_view_impl.h b/content/renderer/render_view_impl.h
index 55508b89efa69eb873a8875113bad25ee32e01c0..e48be4d78fc3df1b153732dc43b2e629bc035e23 100644
--- a/content/renderer/render_view_impl.h
+++ b/content/renderer/render_view_impl.h
@@ -1035,11 +1035,6 @@ class CONTENT_EXPORT RenderViewImpl
   // states for the sizes).
   base::OneShotTimer<RenderViewImpl> check_preferred_size_timer_;
 
-  // These store the "is main frame is scrolled all the way to the left
-  // or right" state that was last sent to the browser.
-  bool cached_is_main_frame_pinned_to_left_;
-  bool cached_is_main_frame_pinned_to_right_;
-
   // Bookkeeping to suppress redundant scroll and focus requests for an already
   // scrolled and focused editable node.
   bool has_scrolled_focused_editable_node_into_rect_;