diff -r 000000000000 -r 4f2f89ce4247 WebCore/rendering/RenderIFrame.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/rendering/RenderIFrame.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2010 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 COMPUTER, 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 COMPUTER, 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 "RenderIFrame.h"
+
+#include "FrameView.h"
+#include "HTMLNames.h"
+#include "HTMLIFrameElement.h"
+#include "RenderView.h"
+#include "Settings.h"
+
+namespace WebCore {
+
+using namespace HTMLNames;
+    
+RenderIFrame::RenderIFrame(Element* element)
+    : RenderFrameBase(element)
+{
+}
+
+void RenderIFrame::calcHeight()
+{
+    RenderPart::calcHeight();
+    if (!flattenFrame())
+         return;
+
+    HTMLIFrameElement* frame = static_cast<HTMLIFrameElement*>(node());
+    bool isScrollable = frame->scrollingMode() != ScrollbarAlwaysOff;
+
+    if (isScrollable || !style()->height().isFixed()) {
+        FrameView* view = static_cast<FrameView*>(widget());
+        if (!view)
+            return;
+        int border = borderTop() + borderBottom();
+        setHeight(max(height(), view->contentsHeight() + border));
+    }
+}
+
+void RenderIFrame::calcWidth()
+{
+    RenderPart::calcWidth();
+    if (!flattenFrame())
+        return;
+
+    HTMLIFrameElement* frame = static_cast<HTMLIFrameElement*>(node());
+    bool isScrollable = frame->scrollingMode() != ScrollbarAlwaysOff;
+
+    if (isScrollable || !style()->width().isFixed()) {
+        FrameView* view = static_cast<FrameView*>(widget());
+        if (!view)
+            return;
+        int border = borderLeft() + borderRight();
+        setWidth(max(width(), view->contentsWidth() + border));
+    }
+}
+
+bool RenderIFrame::flattenFrame()
+{
+    if (!node() || !node()->hasTagName(iframeTag))
+        return false;
+
+    HTMLIFrameElement* element = static_cast<HTMLIFrameElement*>(node());
+    bool isScrollable = element->scrollingMode() != ScrollbarAlwaysOff;
+
+    if (!isScrollable && style()->width().isFixed()
+        && style()->height().isFixed())
+        return false;
+
+    Frame* frame = element->document()->frame();
+    bool enabled = frame && frame->settings()->frameFlatteningEnabled();
+
+    if (!enabled || !frame->page())
+        return false;
+
+    FrameView* view = frame->page()->mainFrame()->view();
+    if (!view)
+        return false;
+
+    // Do not flatten offscreen inner frames during frame flattening.
+    return absoluteBoundingBoxRect().intersects(IntRect(IntPoint(0, 0), view->contentsSize()));
+}
+
+void RenderIFrame::layout()
+{
+    ASSERT(needsLayout());
+
+    RenderPart::calcWidth();
+    RenderPart::calcHeight();
+
+    if (flattenFrame()) {
+        layoutWithFlattening(style()->width().isFixed(), style()->height().isFixed());
+        return;
+    }
+
+    RenderPart::layout();
+
+    m_overflow.clear();
+    addShadowOverflow();
+
+    setNeedsLayout(false);
+}
+
+#if USE(ACCELERATED_COMPOSITING)
+bool RenderIFrame::requiresLayer() const
+{
+    if (RenderPart::requiresLayer())
+        return true;
+    
+    return requiresAcceleratedCompositing();
+}
+
+bool RenderIFrame::requiresAcceleratedCompositing() const
+{
+    if (!node() || !node()->hasTagName(iframeTag))
+        return false;
+
+    // If the contents of the iframe are composited, then we have to be as well.
+    HTMLIFrameElement* element = static_cast<HTMLIFrameElement*>(node());
+    if (Document* contentDocument = element->contentDocument()) {
+        if (RenderView* view = contentDocument->renderView())
+            return view->usesCompositing();
+    }
+
+    return false;
+}
+#endif
+
+}