Allow objects without scrollbars to be scrollable

Source/web/tests/GraphicsLayerTest.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *     notice, this list of conditions and the following disclaimer in the
@@ skipping 100 matching lines @@
     m_platformLayer = m_graphicsLayer->platformLayer();
     ASSERT_TRUE(m_platformLayer);
 
     ASSERT_FALSE(m_platformLayer->hasActiveAnimation());
 }
 
 class FakeScrollableArea : public ScrollableArea {
 public:
     virtual bool isActive() const OVERRIDE { return false; }
     virtual int scrollSize(ScrollbarOrientation) const OVERRIDE { return 100; }
-    virtual int scrollPosition(Scrollbar*) const OVERRIDE { return 0; }
     virtual bool isScrollCornerVisible() const OVERRIDE { return false; }
     virtual IntRect scrollCornerRect() const OVERRIDE { return IntRect(); }
     virtual int visibleWidth() const OVERRIDE { return 10; }
     virtual int visibleHeight() const OVERRIDE { return 10; }
     virtual IntSize contentsSize() const OVERRIDE { return IntSize(100, 100); }
     virtual bool scrollbarsCanBeActive() const OVERRIDE { return false; }
     virtual ScrollableArea* enclosingScrollableArea() const OVERRIDE { return 0; }
     virtual IntRect scrollableAreaBoundingBox() const OVERRIDE { return IntRect(); }
     virtual void invalidateScrollbarRect(Scrollbar*, const IntRect&) OVERRIDE { }
     virtual void invalidateScrollCornerRect(const IntRect&) OVERRIDE { }
+    virtual bool userInputScrollable(ScrollbarOrientation) const OVERRIDE { return true; }
+    virtual int pageStep(ScrollbarOrientation) const OVERRIDE { return 0; }
+    virtual IntPoint minimumScrollPosition() const OVERRIDE { return IntPoint(); }
+    virtual IntPoint maximumScrollPosition() const OVERRIDE
+    {
+        return IntPoint(contentsSize().width() - visibleWidth(), contentsSize().height() - visibleHeight());
+    }
 
     virtual void setScrollOffset(const IntPoint& scrollOffset) OVERRIDE { m_scrollPosition = scrollOffset; }
     virtual IntPoint scrollPosition() const OVERRIDE { return m_scrollPosition; }
 
 private:
     IntPoint m_scrollPosition;
 };
 
 TEST_F(GraphicsLayerTest, applyScrollToScrollableArea)
 {
@@ skipping 13 matching lines @@
     EXPECT_FALSE(m_graphicsLayer->contentsLayer());
 
     m_graphicsLayer->setContentsToSolidColor(Color::white);
     EXPECT_TRUE(m_graphicsLayer->contentsLayer());
 
     m_graphicsLayer->setContentsToSolidColor(Color());
     EXPECT_FALSE(m_graphicsLayer->contentsLayer());
 }
 
 } // namespace