Differentiate invisible cursor mode and disabled mouse events mode.

content/port/browser/render_widget_host_view_port.h

Index: content/port/browser/render_widget_host_view_port.h
diff --git a/content/port/browser/render_widget_host_view_port.h b/content/port/browser/render_widget_host_view_port.h
index 248681ea4a04778f71c7edd27d01f78b20e38337..0e4b9f9b628228f83c5499976f3bd7c38ff3ae73 100644
--- a/content/port/browser/render_widget_host_view_port.h
+++ b/content/port/browser/render_widget_host_view_port.h
@@ -152,6 +152,9 @@ class CONTENT_EXPORT RenderWidgetHostViewPort : public RenderWidgetHostView {
                                       const gfx::Rect& end_rect,
                                       WebKit::WebTextDirection end_direction) {}
 
+  // Notifies the view that the scroll offset has changed.
+  virtual void ScrollOffsetChanged(const gfx::Vector2d& offset) {};
+
   // Allocate a backing store for this view.
   virtual BackingStore* AllocBackingStore(const gfx::Size& size) = 0;