Fix switching interceptor if element needs to upgraded after custom element is registered

Source/bindings/core/dart/DartJsInterop.cpp

Index: Source/bindings/core/dart/DartJsInterop.cpp
diff --git a/Source/bindings/core/dart/DartJsInterop.cpp b/Source/bindings/core/dart/DartJsInterop.cpp
index 7d6498dc64925223ce02e25b1cf395316bb3d055..408e0e10f0fa89366a809d57a7b72d37708f5ff2 100644
--- a/Source/bindings/core/dart/DartJsInterop.cpp
+++ b/Source/bindings/core/dart/DartJsInterop.cpp
@@ -759,6 +759,10 @@ Dart_Handle JsObject::createTyped(v8::Local<v8::Object> object, DartDOMData* dom
     Dart_Handle wrapper = DartDOMWrapper::createWrapperForType<JsObject>(domData, jsObject.get(), JsObject::dartClassId, interceptorData->m_type);
 
     if (interceptorData->m_isCustomElement) {
+        // Need to cache immediately in case we call back and forth between Dart and JS.
+        ASSERT(Dart_IsInstance(wrapper));
+        cache->m_typedInterop = Dart_NewPersistentHandle(wrapper);
+
         Dart_Handle ret = Dart_InvokeConstructor(wrapper, Dart_NewStringFromCString("created"), 0, 0);
         if (Dart_IsError(ret)) {
             DartUtilities::reportProblem(domData->scriptExecutionContext(), ret);
@@ -772,18 +776,21 @@ Dart_Handle JsObject::createTyped(v8::Local<v8::Object> object, DartDOMData* dom
             // We need a fresh JsObject to create a new DOM wrapper.
             jsObject = JsObject::create(object, v8Isolate);
             wrapper = DartDOMWrapper::createWrapperForType<JsObject>(domData, jsObject.get(), JsObject::dartClassId, domData->htmlElementType());
+            // Need to cache immediately in case we call back and forth between Dart and JS.
+            ASSERT(Dart_IsInstance(wrapper));
+            cache->m_typedInterop = Dart_NewPersistentHandle(wrapper);
         }
+    } else {
+        // Simulate the behavior of the Dart dev compiler where new List() is
+        // equivalent to a JavaScript array. We accomplish this by creating a
+        // JavaScript object that fakes that it is a JavaScript array but is
+        // actually backed by a Dart list. This is not a breaking change as
+        // existing Dart-JS interop passed arrays as opaque Dart handles.
+        // The jsify method can still be called if you wish to create a copy
+        // of a json like Dart data structure.
+        ASSERT(Dart_IsInstance(wrapper));
+        cache->m_typedInterop = Dart_NewPersistentHandle(wrapper);
     }
-
-    ASSERT(Dart_IsInstance(wrapper));
-    // Simulate the behavior of the Dart dev compiler where new List() is
-    // equivalent to a JavaScript array. We accomplish this by creating a
-    // JavaScript object that fakes that it is a JavaScript array but is
-    // actually backed by a Dart list. This is not a breaking change as
-    // existing Dart-JS interop passed arrays as opaque Dart handles.
-    // The jsify method can still be called if you wish to create a copy
-    // of a json like Dart data structure.
-    cache->m_typedInterop = Dart_NewPersistentHandle(wrapper);
     return wrapper;
 }
 
@@ -1697,6 +1704,64 @@ fail:
     ASSERT_NOT_REACHED();
 }
 
+// Callback to force an instance to adopt a a specific custom element type.
+// Element accessed before custom class registerElement called.  After which
+// each element with 'is' attribute custom type createdCallback is called with
+// the element to upgrade.
+static void setInstanceInterceptorCustomUpgradeCallback(Dart_NativeArguments args)
+{
+    Dart_Handle exception = 0;
+    {
+        DartDOMData* domData = static_cast<DartDOMData*>(Dart_GetNativeIsolateData(args));
+        auto v8Isolate = domData->v8Isolate();
+        v8::Local<v8::Context> context = domData->v8Context();
+        JsInteropScopes scopes(args, context);
+        JsObject* jsObject = toJsObject(args, 0, exception);
+        if (exception)
+            goto fail;
+        v8::Local<v8::Object> v8Object = jsObject->localV8Object(v8Isolate);
+        if (scopes.handleJsException(&exception))
+            goto fail;
+
+        // Get the type of the element (check to see if the interceptor is the
+        // CustomElementType).
+        Dart_Handle arg0 = Dart_GetNativeArgument(args, 0);
+        Dart_Handle dartType = Dart_InstanceGetType(arg0);
+        ASSERT(Dart_IsType(dartType));
+        Dart_Handle instanceType = Dart_TypeName(dartType);
+
+        // Get the interceptor
+        auto cache = domData->m_dartHandles.get(v8Object, v8Isolate);
+        InterceptorData* interceptor = jsObject->computeInterceptor(v8Object, domData, cache);
+
+        // Get the interceptor's custom element type.
+        Dart_Handle interceptorType = Dart_HandleFromPersistent(interceptor->m_type);
+        ASSERT(Dart_IsType(interceptorType));
+        Dart_Handle customType = Dart_TypeName(interceptorType);
+        ASSERT(Dart_IsType(customType));
+
+        bool equal = false;
+        Dart_ObjectEquals(instanceType, customType, &equal);
+        if (!equal) {
+          // Type of the instance isn't the same as the custom element type so
+          // then we must change the interceptor.  Upgrade to the registered
+          // element.
+          RELEASE_ASSERT(interceptor->m_isCustomElement);
+          cache->m_typedInterop = 0; // Clear existing handle.
+          scopes.setReturnValue(JsObject::createTyped(v8Object, domData, interceptor, cache));
+
+          if (scopes.handleJsException(&exception))
+            goto fail;
+        }
+        return;
+    }
+
+fail:
+    Dart_ThrowException(exception);
+    ASSERT_NOT_REACHED();
+}
+
+
 static void callMethodCallbackHelper(Dart_NativeArguments args, bool legacy)
 {
     Dart_Handle exception = 0;
@@ -2386,6 +2451,7 @@ static DartNativeEntry nativeEntries[] = {
     { JsInteropInternal::defineInterceptorCustomElementCallback, 2, "Utils_defineInterceptorCustomElement" },
     { JsInteropInternal::defineInterceptorCallback, 2, "Utils_defineInterceptor" },
     { JsInteropInternal::setInstanceInterceptorCallback, 3, "Utils_setInstanceInterceptor" },
+    { JsInteropInternal::setInstanceInterceptorCustomUpgradeCallback, 1, "Utils_setInstanceInterceptorCustomUpgrade" },
     { JsInteropInternal::initializeCustomElement, 1, "Utils_initializeCustomElement" },
 
     { JsInteropInternal::toTypedObjectCallback, 1, "JSNative_toTypedObject" },