Support display: contents for elements, first-line and first-letter pseudos.

third_party/WebKit/Source/core/dom/Element.h

Index: third_party/WebKit/Source/core/dom/Element.h
diff --git a/third_party/WebKit/Source/core/dom/Element.h b/third_party/WebKit/Source/core/dom/Element.h
index bf894d78d7eea157064b794058ce63c6e7e50d92..d1eef7f07b2c2e3a2dbf85072e5f8e0ef613c3c3 100644
--- a/third_party/WebKit/Source/core/dom/Element.h
+++ b/third_party/WebKit/Source/core/dom/Element.h
@@ -440,8 +440,17 @@ class CORE_EXPORT Element : public ContainerNode {
   // stored on the Element, computes the ComputedStyle and stores it on the
   // Element’s ElementRareData.  Used for getComputedStyle when Element is
   // display none.
+  //
+  // Also, note that the same is used to store "display: contents" elements
+  // styles.
   const ComputedStyle* ensureComputedStyle(PseudoId = PseudoIdNone);
 
+  // Returns the display: contents style.
+  ComputedStyle* displayContentsStyle() const;

[jfernandez, 2016/10/27 17:08:01]

I guess we want the return value to be const.

+
+  // Stores the "display: contents" style of the element.
+  void storeDisplayContentsStyle(ComputedStyle&);
+
   // Methods for indicating the style is affected by dynamic updates (e.g.,
   // children changing, our position changing in our sibling list, etc.)
   bool styleAffectedByEmpty() const {