custom-elements: Fix a DCHECK failure with...

custom-elements: Fix a DCHECK failure with external/wpt/custom-elements/upgrading/Node-cloneNode.html.

V0CustomElementRegistrationContext::SetTypeExtension() is not
expected to be called for autonomous custom elements. Element::
AttributeChangedFromParserOrByCloning() should check it.

Bug: 805061
Change-Id: Ie91256bb6b6b8671d4a6a65374db31394a08d2ea
Reviewed-on: https://chromium-review.googlesource.com/897169Reviewed-by: Yoshifumi Inoue <yosin@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533972}

third_party/WebKit/LayoutTests/TestExpectations

@@ -2215,7 +2215,6 @@ crbug.com/626703 external/wpt/workers/opaque-origin.html [ Failure Crash Timeout
 crbug.com/626703 external/wpt/html/rendering/non-replaced-elements/margin-collapsing-quirks/multicol-quirks-mode.html [ Pass Crash ]
 crbug.com/626703 external/wpt/html/rendering/non-replaced-elements/margin-collapsing-quirks/multicol-standards-mode.html [ Pass Crash Failure ]
 crbug.com/762017 external/wpt/html/semantics/embedded-content/media-elements/video_loop_base.html [ Pass Crash ]
-crbug.com/805061 external/wpt/custom-elements/upgrading/Node-cloneNode.html [ Crash ]
 crbug.com/807954 external/wpt/service-workers/service-worker/fetch-event-respond-with-readable-stream-chunk.https.html [ Crash ]
 crbug.com/807954 virtual/outofblink-cors/external/wpt/service-workers/service-worker/fetch-event-respond-with-readable-stream-chunk.https.html [ Crash ]
 

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

@@ -1505,7 +1505,7 @@ inline void Element::AttributeChangedFromParserOrByCloning(
     const QualifiedName& name,
     const AtomicString& new_value,
     AttributeModificationReason reason) {
-  if (name == isAttr)
+  if (name == isAttr && !V0CustomElement::IsValidName(localName()))
     V0CustomElementRegistrationContext::SetTypeExtension(this, new_value);
   AttributeChanged(
       AttributeModificationParams(name, g_null_atom, new_value, reason));