diff -r 000000000000 -r 4f2f89ce4247 WebCore/rendering/LayoutState.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/rendering/LayoutState.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) 2007 Apple 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
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
+ */
+
+#include "config.h"
+#include "LayoutState.h"
+
+#include "RenderArena.h"
+#include "RenderInline.h"
+#include "RenderLayer.h"
+#include "RenderView.h"
+
+namespace WebCore {
+
+LayoutState::LayoutState(LayoutState* prev, RenderBox* renderer, const IntSize& offset)
+    : m_next(prev)
+#ifndef NDEBUG
+    , m_renderer(renderer)
+#endif
+{
+    ASSERT(m_next);
+
+    bool fixed = renderer->isPositioned() && renderer->style()->position() == FixedPosition;
+    if (fixed) {
+        // FIXME: This doesn't work correctly with transforms.
+        FloatPoint fixedOffset = renderer->view()->localToAbsolute(FloatPoint(), true);
+        m_offset = IntSize(fixedOffset.x(), fixedOffset.y()) + offset;
+    } else
+        m_offset = prev->m_offset + offset;
+
+    if (renderer->isRelPositioned()) {
+        if (renderer->hasLayer())
+            m_offset += renderer->layer()->relativePositionOffset();
+    } else if (renderer->isPositioned() && !fixed) {
+        if (RenderObject* container = renderer->container()) {
+            if (container->isRelPositioned() && container->isRenderInline())
+                m_offset += toRenderInline(container)->relativePositionedInlineOffset(renderer);
+        }
+    }
+
+    m_clipped = !fixed && prev->m_clipped;
+    if (m_clipped)
+        m_clipRect = prev->m_clipRect;
+
+    if (renderer->hasOverflowClip()) {
+        RenderLayer* layer = renderer->layer();
+        IntRect clipRect(toPoint(m_offset) + renderer->view()->layoutDelta(), layer->size());
+        if (m_clipped)
+            m_clipRect.intersect(clipRect);
+        else {
+            m_clipRect = clipRect;
+            m_clipped = true;
+        }
+        m_offset -= layer->scrolledContentOffset();
+    }
+
+    m_layoutDelta = m_next->m_layoutDelta;
+
+    // FIXME: <http://bugs.webkit.org/show_bug.cgi?id=13443> Apply control clip if present.
+}
+
+LayoutState::LayoutState(RenderObject* root)
+    : m_clipped(false)
+    , m_next(0)
+#ifndef NDEBUG
+    , m_renderer(root)
+#endif
+{
+    RenderObject* container = root->container();
+    FloatPoint absContentPoint = container->localToAbsolute(FloatPoint(), false, true);
+    m_offset = IntSize(absContentPoint.x(), absContentPoint.y());
+
+    if (container->hasOverflowClip()) {
+        RenderLayer* layer = toRenderBoxModelObject(container)->layer();
+        m_clipped = true;
+        m_clipRect = IntRect(toPoint(m_offset), layer->size());
+        m_offset -= layer->scrolledContentOffset();
+    }
+}
+
+#ifndef NDEBUG
+static bool inLayoutStateDestroy;
+#endif
+
+void LayoutState::destroy(RenderArena* renderArena)
+{
+#ifndef NDEBUG
+    inLayoutStateDestroy = true;
+#endif
+    delete this;
+#ifndef NDEBUG
+    inLayoutStateDestroy = false;
+#endif
+    renderArena->free(*(size_t*)this, this);
+}
+
+void* LayoutState::operator new(size_t sz, RenderArena* renderArena) throw()
+{
+    return renderArena->allocate(sz);
+}
+
+void LayoutState::operator delete(void* ptr, size_t sz)
+{
+    ASSERT(inLayoutStateDestroy);
+    *(size_t*)ptr = sz;
+}
+
+} // namespace WebCore