Remove RenderWidgetHostView*::DidUpdateBackingStore.

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 92c9018affc6694360bc624dda22831f9686aadd..7a41e5642087833da3e083ed8b8a3356b6a01ed3 100644
--- a/content/port/browser/render_widget_host_view_port.h
+++ b/content/port/browser/render_widget_host_view_port.h
@@ -115,30 +115,6 @@ class CONTENT_EXPORT RenderWidgetHostViewPort : public RenderWidgetHostView,
       const std::vector<gfx::Rect>& character_bounds) = 0;
 #endif
 
-  // Informs the view that a portion of the widget's backing store was scrolled
-  // and/or painted.  The view should ensure this gets copied to the screen.
-  //
-  // If the scroll_rect is non-empty, then a portion of the widget's backing
-  // store was scrolled by dx pixels horizontally and dy pixels vertically.
-  // The exposed rect from the scroll operation is included in copy_rects.
-  //
-  // There are subtle performance implications here.  The RenderWidget gets sent
-  // a paint ack after this returns, so if the view only ever invalidates in
-  // response to this, then on Windows, where WM_PAINT has lower priority than
-  // events which can cause renderer resizes/paint rect updates, e.g.
-  // drag-resizing can starve painting; this function thus provides the view its
-  // main chance to ensure it stays painted and not just invalidated.  On the
-  // other hand, if this always blindly paints, then if we're already in the
-  // midst of a paint on the callstack, we can double-paint unnecessarily.
-  // (Worse, we might recursively call RenderWidgetHost::GetBackingStore().)
-  // Thus implementers should generally paint as much of |rect| as possible
-  // synchronously with as little overpainting as possible.
-  virtual void DidUpdateBackingStore(
-      const gfx::Rect& scroll_rect,
-      const gfx::Vector2d& scroll_delta,
-      const std::vector<gfx::Rect>& copy_rects,
-      const std::vector<ui::LatencyInfo>& latency_info) = 0;
-
   // Notifies the View that the renderer has ceased to exist.
   virtual void RenderProcessGone(base::TerminationStatus status,
                                  int error_code) = 0;