Make cluster creation independent of fingerprinting. Keep track of current

Source/core/frame/FrameView.cpp

Index: Source/core/frame/FrameView.cpp
diff --git a/Source/core/frame/FrameView.cpp b/Source/core/frame/FrameView.cpp
index e379a3674eaba1695d2bce225ccb10061a7e657b..c4f9e0d185f6c21f584111dfcd43dfe23f132735 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -865,9 +865,6 @@ void FrameView::performPreLayoutTasks()
     // the layout beats any sort of style recalc update that needs to occur.
     TemporaryChange<bool> changeDoingPreLayoutStyleUpdate(m_doingPreLayoutStyleUpdate, true);
     document->updateStyleIfNeeded();
-
-    if (FastTextAutosizer* textAutosizer = document->fastTextAutosizer())
-        textAutosizer->prepareForLayout();

[pdr., 2013/12/21 01:46:57]

I think we still need a mechanism for calling setNeedsLayout() on all blocks
that may depend on a multiplier change. For example, imagine blocks A, B, and C
all depend on a common multiplier but only blocks A and B get called for
layout().

[skobes, 2014/01/07 03:12:37]

I'm not sure I follow.  There are three issues I can think of:

(1) For global changes (autosizing enabled/disabled via inspector, font scale
factor changed in preferences, window resize) we have to make sure the
multipliers get recomputed.  But I thought TextAutosizer::recalculateMultipliers
would handle this already?

(2) If there is a partial layout, we need to make sure the cluster stack has all
the ancestor clusters of the element being processed.  I think we talked about
walking up the tree from beginLayout in this case?  Let's sync tomorrow about
this.

(3) If one cluster in a supercluster is modified or removed, we won't recompute
the multiplier on the other clusters.  I'm not sure this is actually a problem,
it just means we might ignore the fingerprints if a page is adding and removing
stuff via script.

 }
 
 void FrameView::performLayout(RenderObject* rootForThisLayout, bool inSubtreeLayout)