Implement the script parts of custom element upgrade steps.

third_party/WebKit/Source/bindings/core/v8/custom/V8HTMLElementCustom.cpp

Index: third_party/WebKit/Source/bindings/core/v8/custom/V8HTMLElementCustom.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/custom/V8HTMLElementCustom.cpp b/third_party/WebKit/Source/bindings/core/v8/custom/V8HTMLElementCustom.cpp
index 622621df4af221cf0d4d53b8a1e6ae8d626d536d..a7251482a4aae8584ef14e2f54ed45c409a0f41b 100644
--- a/third_party/WebKit/Source/bindings/core/v8/custom/V8HTMLElementCustom.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/custom/V8HTMLElementCustom.cpp
@@ -12,6 +12,7 @@
 #include "bindings/core/v8/V8DOMWrapper.h"
 #include "bindings/core/v8/V8ThrowException.h"
 #include "core/dom/Document.h"
+#include "core/dom/ExceptionCode.h"
 #include "core/dom/custom/CustomElementsRegistry.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "platform/RuntimeEnabledFeatures.h"
@@ -28,48 +29,76 @@ void V8HTMLElement::constructorCustom(
 
     if (!RuntimeEnabledFeatures::customElementsV1Enabled()
         || !scriptState->world().isMainWorld()) {
-        V8ThrowException::throwTypeError(info.GetIsolate(), "Illegal constructor");
+        V8ThrowException::throwTypeError(
+            info.GetIsolate(),
+            "Illegal constructor");
         return;
     }
 
     LocalDOMWindow* window = scriptState->domWindow();
-    ScriptCustomElementDefinition* def =
+    ScriptCustomElementDefinition* definition =
         ScriptCustomElementDefinition::forConstructor(
             scriptState,
             window->customElements(),
             info.NewTarget());
-    if (!def) {
+    if (!definition) {
         V8ThrowException::throwTypeError(isolate, "Illegal constructor");
         return;
     }
 
-    // TODO(dominicc): Implement cases where the definition's
-    // construction stack is not empty when parser-creation is
-    // implemented.
-
     ExceptionState exceptionState(
         ExceptionState::ConstructionContext,
         "HTMLElement",
         info.Holder(),
         isolate);
-    Element* element = window->document()->createElement(
-        def->descriptor().localName(),
-        AtomicString(),
-        exceptionState);
-    if (exceptionState.throwIfNeeded())
-        return;
+
+    Element* element;
+    if (definition->constructionStack().isEmpty()) {
+        // This is an element being created with 'new' from script
+        element = window->document()->createElement(
+            definition->descriptor().localName(),
+            AtomicString(),
+            exceptionState);
+        if (exceptionState.throwIfNeeded())
+            return;
+    } else {
+        element = definition->constructionStack().last();
+        if (element) {
+            // This is an element being upgraded that has called super
+            definition->constructionStack().last().clear();
+        } else {
+            // During upgrade an element has invoked the same constructor
+            // before calling 'super' and that invocation has poached the
+            // element.
+            exceptionState.throwDOMException(
+                InvalidStateError,
+                "this instance is already constructed");
+            exceptionState.throwIfNeeded();
+            return;
+        }
+    }
     const WrapperTypeInfo* wrapperType = element->wrapperTypeInfo();
     v8::Local<v8::Object> wrapper = V8DOMWrapper::associateObjectWithWrapper(
         isolate,
         element,
         wrapperType,
         info.This());
+    // If the element had a wrapper, we now update and return that
+    // instead.
+    v8SetReturnValue(info, wrapper);
 
-    if (!v8CallBoolean(wrapper->SetPrototype(
+    v8CallOrCrash(wrapper->SetPrototype(
         scriptState->context(),
-        def->prototype()))) {
-        return;
-    }
+        definition->prototype()));
+
+    // TODO(dominicc): These elements should be 'undefined', not
+    // 'uncustomized', on creation. Investigate why some elements are
+    // running around uncustomized.
+    if (element->getCustomElementState() == CustomElementState::Uncustomized)
+        element->setCustomElementState(CustomElementState::Undefined);
+    // TODO(dominicc): Move this to the exactly correct place when
+    // https://github.com/whatwg/html/issues/1297 is closed.
+    element->setCustomElementState(CustomElementState::Custom);
 }
 
 } // namespace blink