Add infrastructure for partial layouts

Source/core/rendering/RenderObject.cpp

Index: Source/core/rendering/RenderObject.cpp
diff --git a/Source/core/rendering/RenderObject.cpp b/Source/core/rendering/RenderObject.cpp
index 3e6731e83b7268cdf9db7154f7cc1b5e3a42710b..930cc712f57af435b554fca1fb40d6a65a58f028 100644
--- a/Source/core/rendering/RenderObject.cpp
+++ b/Source/core/rendering/RenderObject.cpp
@@ -746,6 +746,12 @@ void RenderObject::checkBlockPositionedObjectsNeedLayout()
     if (isRenderBlock())
         toRenderBlock(this)->checkPositionedObjectsNeedLayout();
 }
+
+void RenderObject::checkNotInPartialLayout()
+{
+    // During partial layout, setNeedsLayout(true or false) should not be called.
+    ASSERT(!frameView()->shouldStopPartialLayout());
+}
 #endif
 
 void RenderObject::setPreferredLogicalWidthsDirty(bool shouldBeDirty, MarkingBehavior markParents)
@@ -2778,6 +2784,14 @@ bool RenderObject::nodeAtPoint(const HitTestRequest&, HitTestResult&, const HitT
     return false;
 }
 
+FrameView* RenderObject::frameView() const

[eseidel, 2013/08/20 21:00:39]

I think we should explain why this should never be null for RenderObject and
ASSERT it.  I would do this in a separate patch.

+{
+    // FIXME: Should we check isRooted()?

[esprehn, 2013/08/23 20:47:27]

There's no reason to.

[pdr., 2013/08/26 05:50:40]

Done.

+    if (RenderView* renderView = view())

[esprehn, 2013/08/23 20:47:27]

Don't do this, just do return document()->view();

What you have is actually:

m_node->document()->renderView()->frameView()

instead you want:

m_node->document()->view()

which is what document()->view() does.

[pdr., 2013/08/26 05:50:40]

Done.

+        return renderView->frameView();
+    return 0;
+}
+
 void RenderObject::scheduleRelayout()
 {
     if (isRenderView()) {