1 files changed, 14 insertions, 9 deletions
diff --git a/Source/WebCore/platform/graphics/TiledBacking.h b/Source/WebCore/platform/graphics/TiledBacking.h
index 70012b117..1c74f09a2 100644
--- a/Source/WebCore/platform/graphics/TiledBacking.h
+++ b/Source/WebCore/platform/graphics/TiledBacking.h
@@ -32,21 +32,26 @@ class IntRect;
 
 class TiledBacking {
 public:
-    TiledBacking()
-        : m_scrollingPerformanceLoggingEnabled(0)
-    { }
     virtual ~TiledBacking() { }
 
     virtual void visibleRectChanged(const IntRect&) = 0;
     virtual void setIsInWindow(bool) = 0;
-    virtual void setCanHaveScrollbars(bool) = 0;
-    virtual void forceRepaint() = 0;
 
-    void setScrollingPerformanceLoggingEnabled(bool flag)  { m_scrollingPerformanceLoggingEnabled = flag; }
-    bool scrollingPerformanceLoggingEnabled() const { return m_scrollingPerformanceLoggingEnabled; }
+    enum {
+        CoverageForVisibleArea = 0,
+        CoverageForVerticalScrolling = 1 << 0,
+        CoverageForHorizontalScrolling = 1 << 1,
+        CoverageForScrolling = CoverageForVerticalScrolling | CoverageForHorizontalScrolling
+    };
+    typedef unsigned TileCoverage;
+
+    virtual void setTileCoverage(TileCoverage) = 0;
+    virtual TileCoverage tileCoverage() const = 0;
+
+    virtual void forceRepaint() = 0;
 
-private:
-    bool m_scrollingPerformanceLoggingEnabled;
+    virtual void setScrollingPerformanceLoggingEnabled(bool) = 0;
+    virtual bool scrollingPerformanceLoggingEnabled() const = 0;
 };
 
 } // namespace WebCore