Remove RenderFlowThread::offsetFromLogicalTopOfFirstRegion().

Source/core/rendering/RenderBlock.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 3627 matching lines @@
 {
     if (RenderFlowThread* flowThread = flowThreadContainingBlock())
         flowThread->updateMinimumPageHeight(offsetFromLogicalTopOfFirstPage() + offset, minHeight);
     else if (ColumnInfo* colInfo = view()->layoutState()->columnInfo())
         colInfo->updateMinimumColumnHeight(minHeight);
 }
 
 LayoutUnit RenderBlock::offsetFromLogicalTopOfFirstPage() const
 {
     LayoutState* layoutState = view()->layoutState();
-    if (layoutState && !layoutState->isPaginated())
-        return 0;
-
-    RenderFlowThread* flowThread = flowThreadContainingBlock();
-    if (flowThread)
-        return flowThread->offsetFromLogicalTopOfFirstRegion(this);
-
-    if (layoutState) {
-        ASSERT(layoutState->renderer() == this);
-
-        LayoutSize offsetDelta = layoutState->layoutOffset() - layoutState->pageOffset();
-        return isHorizontalWritingMode() ? offsetDelta.height() : offsetDelta.width();
-    }
-
-    ASSERT_NOT_REACHED();
-    return 0;
+    RELEASE_ASSERT(layoutState);
+    if (!layoutState->isPaginated())
+        return LayoutUnit();
+    // It would be possible to remove the requirement that this block be the one currently being
+    // laid out, but nobody needs that at the moment.
+    ASSERT(layoutState->renderer() == this);
+    LayoutSize offsetDelta = layoutState->layoutOffset() - layoutState->pageOffset();
+    return isHorizontalWritingMode() ? offsetDelta.height() : offsetDelta.width();
 }
 
 LayoutUnit RenderBlock::collapsedMarginBeforeForChild(const RenderBox& child) const
 {
     // If the child has the same directionality as we do, then we can just return its
     // collapsed margin.
     if (!child.isWritingModeRoot())
         return child.collapsedMarginBefore();
 
     // The child has a different directionality.  If the child is parallel, then it's just
@@ skipping 241 matching lines @@
 void RenderBlock::showLineTreeAndMark(const InlineBox* markedBox1, const char* markedLabel1, const InlineBox* markedBox2, const char* markedLabel2, const RenderObject* obj) const
 {
     showRenderObject();
     for (const RootInlineBox* root = firstRootBox(); root; root = root->nextRootBox())
         root->showLineTreeAndMark(markedBox1, markedLabel1, markedBox2, markedLabel2, obj, 1);
 }
 
 #endif
 
 } // namespace blink