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

content/renderer/render_widget.h

Index: content/renderer/render_widget.h
diff --git a/content/renderer/render_widget.h b/content/renderer/render_widget.h
index b4e28dc394f49d227db3fb974f52e078cfcffe38..f459fdf89524339f9bd78242d68fe8335cb8e395 100644
--- a/content/renderer/render_widget.h
+++ b/content/renderer/render_widget.h
@@ -274,11 +274,6 @@ class CONTENT_EXPORT RenderWidget
   void UpdateCompositionInfo(bool should_update_range);
 #endif
 
-#if defined(OS_MACOSX)
-  void DidChangeScrollbarsForMainFrame(bool has_horizontal_scrollbar,
-                                       bool has_vertical_scrollbar);
-#endif  // defined(OS_MACOSX)
-
 #if defined(OS_ANDROID)
   void DidChangeBodyBackgroundColor(SkColor bg_color);
 #endif
@@ -695,12 +690,6 @@ class CONTENT_EXPORT RenderWidget
   SkColor body_background_color_;
 #endif
 
-#if defined(OS_MACOSX)
-  // These store the "has scrollbars" state last sent to the browser.
-  bool cached_has_main_frame_horizontal_scrollbar_;
-  bool cached_has_main_frame_vertical_scrollbar_;
-#endif  // defined(OS_MACOSX)
-
   scoped_ptr<ScreenMetricsEmulator> screen_metrics_emulator_;
 
   // Popups may be displaced when screen metrics emulation is enabled.