Clarify a role of Shadow DOM related functions

third_party/WebKit/Source/core/html/HTMLContentElement.cpp

Index: third_party/WebKit/Source/core/html/HTMLContentElement.cpp
diff --git a/third_party/WebKit/Source/core/html/HTMLContentElement.cpp b/third_party/WebKit/Source/core/html/HTMLContentElement.cpp
index 8621d34349acf819dabbe5159f4a72ee10343304..a16138ae2418c25e48d83df2c0b24ee2ede3dca6 100644
--- a/third_party/WebKit/Source/core/html/HTMLContentElement.cpp
+++ b/third_party/WebKit/Source/core/html/HTMLContentElement.cpp
@@ -76,7 +76,7 @@ void HTMLContentElement::parseAttribute(const QualifiedName& name, const AtomicS
 {
     if (name == selectAttr) {
         if (ShadowRoot* root = containingShadowRoot()) {
-            if (root->owner())
+            if (!root->isV1() && root->owner())

[kochi, 2016/09/09 06:51:06]

If <content> is in V1 shadow, we don't have to parser select= attribute at all?

i.e.

ShadowRoot* root = containingShadowRoot();

if (!root || root->isV1 || name != selectAttr) {
    InsertionPoint::parseAttribute(...);
    return;
}

// do the rest

[hayato, 2016/09/09 07:03:29]

Yeah, I am aware there are still a lot of TODO things.
I'll address them in bunch of follow-up CLs.

[kochi, 2016/09/09 07:06:58]

Sounds good.

                 root->owner()->willAffectSelector();
         }
         m_shouldParseSelect = true;