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

content/renderer/render_view_impl.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_RENDERER_RENDER_VIEW_IMPL_H_
 #define CONTENT_RENDERER_RENDER_VIEW_IMPL_H_
 
 #include <deque>
 #include <map>
 #include <set>
@@ skipping 1017 matching lines @@
   // View ----------------------------------------------------------------------
 
   // Cache the preferred size of the page in order to prevent sending the IPC
   // when layout() recomputes but doesn't actually change sizes.
   gfx::Size preferred_size_;
 
   // Used to delay determining the preferred size (to avoid intermediate
   // 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_;
   gfx::Rect rect_for_scrolled_focused_editable_node_;
 
   // Helper objects ------------------------------------------------------------
 
   scoped_ptr<RenderFrameImpl> main_render_frame_;
 
   // The next group of objects all implement RenderViewObserver, so are deleted
@@ skipping 137 matching lines @@
   // use the Observer interface to filter IPC messages and receive frame change
   // notifications.
   // ---------------------------------------------------------------------------
 
   DISALLOW_COPY_AND_ASSIGN(RenderViewImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDER_VIEW_IMPL_H_