[css-display] Support display: contents pseudo-elements.

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

Index: third_party/WebKit/Source/core/layout/LayoutObject.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.h b/third_party/WebKit/Source/core/layout/LayoutObject.h
index f59a44bbfcd08d3f4e903cbbc8425c825ebc048f..c12dbe26cc150d7ffc54c4fabb76d11731090e2b 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.h
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.h
@@ -30,6 +30,7 @@
 #include "core/CoreExport.h"
 #include "core/dom/Document.h"
 #include "core/dom/DocumentLifecycle.h"
+#include "core/dom/PseudoElement.h"
 #include "core/editing/PositionWithAffinity.h"
 #include "core/layout/LayoutObjectChildList.h"
 #include "core/layout/MapCoordinatesFlags.h"
@@ -543,6 +544,13 @@ class CORE_EXPORT LayoutObject : public ImageResourceObserver,
   void operator delete(void*);
 
   bool isPseudoElement() const { return node() && node()->isPseudoElement(); }
+  PseudoElement* ownerPseudoElement() {
+    // NB: This also handles anonymous generated content for a given

[rune, 2017/04/04 14:23:41]

What is anonymous generated content?

[emilio, 2017/04/04 15:09:18]

It's my ability to badly word comments. I meant anonymous layout objects for
generated ::before or after (that's why we look directly at m_node and not
node()). Will reword if this ends up being needed.

+    // pseudo-element.
+    return m_node && m_node->isPseudoElement() ? toPseudoElement(m_node)
+                                               : nullptr;
+  }
+  bool isPseudoElementGeneratedContentFor(const PseudoElement&) const;

[rune, 2017/04/04 14:23:41]

This name is incomprehensible. It means that this layout object is generated
content for the passed in pseudo element (::before or ::after)?

[emilio, 2017/04/04 15:09:18]

Yeah, that's the idea. I'm terrible at naming, so I'll try to find a better name
if I can't do the ::first-line simplification for ::before and ::after.

 
   virtual bool isBoxModelObject() const { return false; }
   bool isBR() const { return isOfType(LayoutObjectBr); }
@@ -2064,6 +2072,11 @@ class CORE_EXPORT LayoutObject : public ImageResourceObserver,
   virtual void insertedIntoTree();
   virtual void willBeRemovedFromTree();
 
+  void setPseudoForAnonymous(PseudoElement& pseudo) {

[rune, 2017/04/04 14:23:41]

This also needs a better name if possible.

[emilio, 2017/04/04 15:09:18]

Acknowledged.

+    DCHECK(isAnonymous());
+    m_node = &pseudo;
+  }
+
   void setDocumentForAnonymous(Document* document) {
     DCHECK(isAnonymous());
     m_node = document;