[cssom] Add a note pointing out how title behaves in Shadow DOM.

emilio · emilio · commit 5cb2170b3ddb · 2018-10-26T03:27:16.000+02:00
Closes w3c#2646
diff --git a/cssom-1/Overview.bs b/cssom-1/Overview.bs
@@ -115,6 +115,7 @@ spec:html; type:element; text:style
 spec:css-namespaces-3; type:dfn; text:namespace prefix
 spec:dom; type:interface; text:Document
 spec:dom; type:interface; text:DocumentOrShadowRoot
+spec:dom; type:dfn; text:in a document tree
 spec:html; type:dfn; text:ascii case-insensitive
 spec:html; type:dfn; text:case-sensitive
 spec:infra; type:dfn; text:list
@@ -820,6 +821,9 @@ represents a style sheet as defined by the CSS specification. In the CSSOM a
   <a>title</a> must be set to the value of that attribute. Whenever the attribute is set, changed or removed, the
   <a>title</a> must be set to the new value of the attribute, or to the empty string if the attribute is absent.
 
+  Note: HTML only <a href="https://html.spec.whatwg.org/#the-style-element:concept-css-style-sheet-title">specifies</a>
+  <a>title</a> to be an attribute of the <a for=CSSStyleSheet>owner node</a>
+  if the node is in <a>in a document tree</a>.
 
 
  <dt><dfn id=concept-css-style-sheet-alternate-flag>alternate flag</dfn>
