Factor out the actual break checking from apply{After,Before}Break().

third_party/WebKit/Source/core/layout/LayoutBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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
@@ skipping 1761 matching lines @@
     m_rareData->m_spannerPlaceholder = nullptr;
 }
 
 void LayoutBox::setPaginationStrut(LayoutUnit strut)
 {
     if (!strut && !m_rareData)
         return;
     ensureRareData().m_paginationStrut = strut;
 }
 
+static bool isForcedBreakAllowed(const LayoutBox* child)
+{
+    // We currently only support forced breaks on in-flow block level elements, which is the minimum
+    // requirement according to the spec.
+    if (child->isInline() || child->isFloatingOrOutOfFlowPositioned())
+        return false;
+    const LayoutBlock* curr = child->containingBlock();
+    if (!curr || !curr->isLayoutBlockFlow())
+        return false;
+    const LayoutView* layoutView = child->view();
+    while (curr && curr != layoutView) {
+        if (curr->isLayoutFlowThread())
+            return true;
+        if (curr->isFloatingOrOutOfFlowPositioned())
+            return false;
+        curr = curr->containingBlock();
+    }
+    return true;
+}
+
+bool LayoutBox::hasForcedBreakBefore() const
+{
+    LayoutFlowThread* flowThread = flowThreadContainingBlock();
+    bool checkColumnBreaks = flowThread;
+    bool checkPageBreaks = !checkColumnBreaks && view()->layoutState()->pageLogicalHeight(); // TODO(mstensho): Once columns can print, we have to check this.

[leviw_travelin_and_unemployed, 2015/10/08 08:29:14]

Can you toss these TODO's on a different line?

+    bool checkBeforeAlways = (checkColumnBreaks && style()->columnBreakBefore() == PBALWAYS)
+        || (checkPageBreaks && style()->pageBreakBefore() == PBALWAYS);
+    return checkBeforeAlways && isForcedBreakAllowed(this);
+}
+
+bool LayoutBox::hasForcedBreakAfter() const
+{
+    LayoutFlowThread* flowThread = flowThreadContainingBlock();
+    bool checkColumnBreaks = flowThread;
+    bool checkPageBreaks = !checkColumnBreaks && view()->layoutState()->pageLogicalHeight(); // TODO(mstensho): Once columns can print, we have to check this.

[leviw_travelin_and_unemployed, 2015/10/08 08:29:14]

Same as above.

+    bool checkAfterAlways = (checkColumnBreaks && style()->columnBreakAfter() == PBALWAYS)

[leviw_travelin_and_unemployed, 2015/10/08 08:29:14]

We should really rename these enums, unless we want to support pages that always
want peanut butter :p

+        || (checkPageBreaks && style()->pageBreakAfter() == PBALWAYS);
+    return checkAfterAlways && isForcedBreakAllowed(this);
+}
+
 LayoutRect LayoutBox::clippedOverflowRectForPaintInvalidation(const LayoutBoxModelObject* paintInvalidationContainer, const PaintInvalidationState* paintInvalidationState) const
 {
     if (style()->visibility() != VISIBLE) {
         PaintLayer* layer = enclosingLayer();
         layer->updateDescendantDependentFlags();
         if (layer->subtreeIsInvisible())
             return LayoutRect();
     }
 
     LayoutRect r = visualOverflowRect();
@@ skipping 2972 matching lines @@
     StyleImage* borderImage = style()->borderImage().image();
     return borderImage && borderImage->canRender(*this, style()->effectiveZoom()) && borderImage->isLoaded();
 }
 
 ShapeOutsideInfo* LayoutBox::shapeOutsideInfo() const
 {
     return ShapeOutsideInfo::isEnabledFor(*this) ? ShapeOutsideInfo::info(*this) : nullptr;
 }
 
 } // namespace blink