Make custom elements work in HTML imports

third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.cpp

Index: third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.cpp
diff --git a/third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.cpp b/third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.cpp
index 6ecc7a8ea89b49ab40328c7981fe22f933eed729..39ce3d93b0d1cc52a63be7d2e63bafd96d1ffd05 100644
--- a/third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.cpp
+++ b/third_party/WebKit/Source/core/dom/custom/CustomElementsRegistry.cpp
@@ -79,6 +79,7 @@ CustomElementsRegistry::CustomElementsRegistry(const LocalDOMWindow* owner)
     , m_v0 (new V0RegistrySet())
     , m_upgradeCandidates(new UpgradeCandidateMap())
 {
+    DCHECK(m_owner->document() == m_owner->document()->contextDocument());

[kochi, 2016/08/22 12:02:00]

Hmm, this is a leftover from Koji's original patch, but as this makes little
sense now (it used to get document as a parameter, but now window).
Removing.

 }
 
 DEFINE_TRACE(CustomElementsRegistry)
@@ -234,6 +235,8 @@ CustomElementDefinition* CustomElementsRegistry::definitionForName(
 
 void CustomElementsRegistry::addCandidate(Element* candidate)
 {
+    DCHECK(candidate->document().contextDocument() == m_owner->document());

[dominicc (has gone to gerrit), 2016/08/22 08:07:36]

This should actually be harmless, but I guess I don't mind either way. Maybe add
a comment.

[kochi, 2016/08/22 12:02:00]

After https://codereview.chromium.org/2252003002/ (Change custom element state
in documents without browsing context) I think this assertion no longer holds.
Removing.

+
     const AtomicString& name = candidate->localName();
     if (nameIsDefined(name) || v0NameIsDefined(name))
         return;
@@ -276,6 +279,7 @@ void CustomElementsRegistry::collectCandidates(
     UpgradeCandidateMap::iterator it = m_upgradeCandidates->find(desc.name());
     if (it == m_upgradeCandidates->end())
         return;
+
     CustomElementUpgradeSorter sorter;
     for (Element* element : *it.get()->value) {
         if (!element || !desc.matches(*element))