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..1ce4732c7c61e138555a98d8f37d4fd6d63ee15f 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 +29,73 @@ 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())
+
+    Element* element;
+    if (definition->constructionStack().isEmpty()) {
+        // This is an element being created with 'new' from script
+        element = window->document()->createElement(

[kojii, 2016/06/03 07:50:42]

nit: this needs to be HTMLElementFactory::createHTLMElement with
DisableCustomElements, but it won't cause problems until
CustomElement::createCustomElement() starts checking defined elements, so we can
defer the fix until then. It should fix CustomElementState being unstable in
your comment below.
Experimental fix at https://codereview.chromium.org/2033253003

+            definition->descriptor().localName(),
+            AtomicString(),
+            exceptionState);
+        if (exceptionState.throwIfNeeded())
+            return;
+    } else if ((element = definition->constructionStack().last())) {

[Sébastien Marchand, 2016/06/03 13:34:33]

This is breaking the Windows PGO builder (and it'll probably break the official
x64 build tomorrow as it use WPO, which will hit this warning as well), here's
the warning for this:
warning C4706: assignment within conditional expression

+        // 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