Do not push the custom element construction stack in some cases.

third_party/WebKit/LayoutTests/custom-elements/spec/construct.html

Index: third_party/WebKit/LayoutTests/custom-elements/spec/construct.html
diff --git a/third_party/WebKit/LayoutTests/custom-elements/spec/construct.html b/third_party/WebKit/LayoutTests/custom-elements/spec/construct.html
index 4d33bb67af06833951a209564bce7701386b520a..4bae58660fdde158d4eb8bd91e59260d09da23be 100644
--- a/third_party/WebKit/LayoutTests/custom-elements/spec/construct.html
+++ b/third_party/WebKit/LayoutTests/custom-elements/spec/construct.html
@@ -122,11 +122,31 @@ test_with_window((w) => {
     }
   }
   w.customElements.define('a-a', A);
+  let e = w.document.createElement('a-a');
+  assert_true(e.matches(':defined'),
+    'constructing an autonomous custom element with create element should ' +
+    'not throw InvalidStateError ' +
+    'and should return a "custom" element');
+}, 'Already constructed marker, create element');
+
+test_with_window((w) => {
+  let flag = true;
+  class A extends w.HTMLElement {
+    constructor() {
+      if (flag) {
+        flag = false;
+        new A();
+      }
+      super();
+    }
+  }
+  w.customElements.define('a-a', A);
+  let d = w.document.createElement('div');
   assert_reports(w, 'INVALID_STATE_ERR', () => {
-    w.document.createElement('a-a');
+    d.innerHTML = '<a-a>';
   }, 'Creating an element that is already constructed marker should report ' +
      'InvalidStateError');
-}, 'Already constructed marker, create element');
+}, 'Already constructed marker, fragment parsing should set marker');
 
 test_with_window((w) => {
   let errors = [];