1 files changed, 5 insertions, 0 deletions
diff --git a/WebCore/platform/ScrollView.h b/WebCore/platform/ScrollView.h
index 7fb5d8e..d6b08b2 100644
--- a/WebCore/platform/ScrollView.h
+++ b/WebCore/platform/ScrollView.h
@@ -127,7 +127,11 @@ public:
     // The visible content rect has a location that is the scrolled offset of the document. The width and height are the viewport width
     // and height. By default the scrollbars themselves are excluded from this rectangle, but an optional boolean argument allows them to be
     // included.
+    // In the situation the client is responsible for the scrolling (ie. with a tiled backing store) it is possible to use
+    // the actualVisibleContentRect instead, though this must be updated manually, e.g after panning ends.
     IntRect visibleContentRect(bool includeScrollbars = false) const;
+    IntRect actualVisibleContentRect() const { return m_actualVisibleContentRect.isEmpty() ? visibleContentRect() : m_actualVisibleContentRect; }
+    void setActualVisibleContentRect(const IntRect& actualVisibleContentRect) { m_actualVisibleContentRect = actualVisibleContentRect; }
     int visibleWidth() const { return visibleContentRect().width(); }
     int visibleHeight() const { return visibleContentRect().height(); }
 
@@ -294,6 +298,7 @@ private:
     // whether it is safe to blit on scroll.
     bool m_canBlitOnScroll;
 
+    IntRect m_actualVisibleContentRect;
     IntSize m_scrollOffset; // FIXME: Would rather store this as a position, but we will wait to make this change until more code is shared.
     IntSize m_fixedLayoutSize;
     IntSize m_contentsSize;