Move showLineTreeAndMark() to LayoutBlockFlow.

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 1641 matching lines @@
         node()->showTreeForThis();
 }
 
 void LayoutObject::showLayoutTreeForThis() const
 {
     showLayoutTree(this, 0);
 }
 
 void LayoutObject::showLineTreeForThis() const
 {
-    if (containingBlock())
-        containingBlock()->showLineTreeAndMark(0, 0, 0, 0, this);
+    if (LayoutBlock* cb = containingBlock()) {
+        if (cb->isLayoutBlockFlow())

[wkorman, 2016/05/04 20:30:41]

Does this change behavior of what we output at all? If so consider updating CL
description.

[mstensho (USE GERRIT), 2016/05/04 20:54:25]

In theory, yes. If someone wants to display the line tree they're in when
they're not in a block container (LayoutBlockFlow) (and therefore doesn't
participate in an inline formatting context), we'll now do nothing, rather than
calling showLayoutObject(), which would be the previous behavior. I see no value
in someone doing something as stupid as that, though. :)

This is debug code, FWIW.

+            toLayoutBlockFlow(cb)->showLineTreeAndMark(0, 0, 0, 0, this);

[wkorman, 2016/05/04 20:30:41]

Use nullptr rather than 0. Is it untoward re: consistency of showXxx() methods
to alter param order so we can just pass this and rely on defaults for the
others?

[mstensho (USE GERRIT), 2016/05/04 20:54:25]

Done.
Deserves a separate CL, if anything. There are multiple callers of
showLineTreeAndMark(), and all I want in this CL is to get rid of line layout
code from LayoutBlock.

+    }
 }
 
 void LayoutObject::showLayoutObject() const
 {
     showLayoutObject(0);
 }
 
 void LayoutObject::showLayoutObject(int printedCharacters) const
 {
     printedCharacters += fprintf(stderr, "%s %p", decoratedName().ascii().data(), this);
@@ skipping 2032 matching lines @@
         const blink::LayoutObject* root = object1;
         while (root->parent())
             root = root->parent();
         root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
     } else {
         fprintf(stderr, "Cannot showLayoutTree. Root is (nil)\n");
     }
 }
 
 #endif