*** DO NOT LAND *** Attempt to understand Regions complexity

Source/core/rendering/FlowThreadController.h

Index: Source/core/rendering/FlowThreadController.h
diff --git a/Source/core/rendering/FlowThreadController.h b/Source/core/rendering/FlowThreadController.h
deleted file mode 100644
index 7f56615d7dec0ca3add99d5a434076d01a20e1c5..0000000000000000000000000000000000000000
--- a/Source/core/rendering/FlowThreadController.h
+++ /dev/null
@@ -1,100 +0,0 @@
-/*
- * Copyright (C) 2012 Adobe Systems Incorporated. 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 THE COPYRIGHT HOLDER "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 THE COPYRIGHT HOLDER 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.
- */
-
-#ifndef FlowThreadController_h
-#define FlowThreadController_h
-
-#include "core/rendering/RenderView.h"
-#include "wtf/ListHashSet.h"
-#include "wtf/OwnPtr.h"
-
-namespace WebCore {
-
-class RenderFlowThread;
-class RenderNamedFlowThread;
-
-typedef ListHashSet<RenderNamedFlowThread*> RenderNamedFlowThreadList;
-
-class FlowThreadController {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    static PassOwnPtr<FlowThreadController> create(RenderView*);
-    ~FlowThreadController();
-
-    RenderFlowThread* currentRenderFlowThread() const { return m_currentRenderFlowThread; }
-    void setCurrentRenderFlowThread(RenderFlowThread* flowThread) { m_currentRenderFlowThread = flowThread; }
-
-    bool isRenderNamedFlowThreadOrderDirty() const { return m_isRenderNamedFlowThreadOrderDirty; }
-    void setIsRenderNamedFlowThreadOrderDirty(bool dirty)
-    {
-        m_isRenderNamedFlowThreadOrderDirty = dirty;
-        if (dirty)
-            m_view->setNeedsLayout();
-    }
-
-    RenderNamedFlowThread* ensureRenderFlowThreadWithName(const AtomicString&);
-    const RenderNamedFlowThreadList* renderNamedFlowThreadList() const { return m_renderNamedFlowThreadList.get(); }
-    bool hasRenderNamedFlowThreads() const { return m_renderNamedFlowThreadList && !m_renderNamedFlowThreadList->isEmpty(); }
-    void layoutRenderNamedFlowThreads();
-    void styleDidChange();
-
-    void registerNamedFlowContentNode(Node*, RenderNamedFlowThread*);
-    void unregisterNamedFlowContentNode(Node*);
-    bool isContentNodeRegisteredWithAnyNamedFlow(const Node*) const;
-
-    bool hasFlowThreadsWithAutoLogicalHeightRegions() const { return m_flowThreadsWithAutoLogicalHeightRegions; }
-    void incrementFlowThreadsWithAutoLogicalHeightRegions() { ++m_flowThreadsWithAutoLogicalHeightRegions; }
-    void decrementFlowThreadsWithAutoLogicalHeightRegions() { ASSERT(m_flowThreadsWithAutoLogicalHeightRegions > 0); --m_flowThreadsWithAutoLogicalHeightRegions; }
-
-    bool updateFlowThreadsNeedingLayout();
-    bool updateFlowThreadsNeedingTwoStepLayout();
-    void updateFlowThreadsIntoConstrainedPhase();
-
-#ifndef NDEBUG
-    bool isAutoLogicalHeightRegionsCountConsistent() const;
-#endif
-
-protected:
-    FlowThreadController(RenderView*);
-    void updateFlowThreadsChainIfNecessary();
-    void resetFlowThreadsWithAutoHeightRegions();
-
-private:
-    RenderView* m_view;
-    RenderFlowThread* m_currentRenderFlowThread;
-    bool m_isRenderNamedFlowThreadOrderDirty;
-    unsigned m_flowThreadsWithAutoLogicalHeightRegions;
-    OwnPtr<RenderNamedFlowThreadList> m_renderNamedFlowThreadList;
-    // maps a content node to its render flow thread.
-    HashMap<const Node*, RenderNamedFlowThread*> m_mapNamedFlowContentNodes;
-};
-
-}
-
-#endif