Dartium support for manual custom element upgrades.

Source/bindings/dart/DartNativeUtilities.cpp

 // Copyright 2012, Google Inc.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //    * Redistributions of source code must retain the above copyright
 // notice, this list of conditions and the following disclaimer.
 //    * Redistributions in binary form must reproduce the above
@@ skipping 219 matching lines @@
         // TODO(vsm): Return isolate future.
         dartController->spawnDomUri(uri);
         return;
     }
 
 fail:
     Dart_ThrowException(exception);
     ASSERT_NOT_REACHED();
 }
 
+void changeElementWrapper(Dart_NativeArguments args)
+{
+    Dart_Handle exception = 0;
+    {
+        Dart_Handle elementWrapper = Dart_GetNativeArgument(args, 0);
+        if (!DartDOMWrapper::subtypeOf(elementWrapper, DartHTMLElement::dartClassId)) {
+            exception = Dart_NewStringFromCString("Invalid class: expected instance of HtmlElement");
+            goto fail;
+        }
+
+        Dart_Handle wrapperType = Dart_GetNativeArgument(args, 1);
+        if (!Dart_IsType(wrapperType)) {

[vsm, 2014/04/16 21:33:05]

How do we validate that this is an allowable type wrt to the element?  

[blois, 2014/04/16 22:18:51]

Much of the code is shared with the custom element registration-
https://codereview.chromium.org/177113014/diff/40001/tools/dom/src/dartium_Cu...

Primary check is that the upgrader has a known native type which can be upgraded
and the runtimeType of the element being upgraded has to match (not just be
assignable).

In addition the native class ID is reused from the original wrapper to the new
wrapper, so the native type cannot change even while the wrapper changes.

+            exception = Dart_NewStringFromCString("Expected instance of Type");
+            goto fail;
+        }
+
+        Dart_Handle newWrapper = DartCustomElementWrapper<HTMLElement>::changeElementWrapper(elementWrapper, wrapperType);
+        if (Dart_IsError(newWrapper)) {
+            exception = newWrapper;
+            goto fail;
+        }
+        Dart_SetReturnValue(args, newWrapper);
+        return;
+    }
+
+fail:
+    Dart_ThrowException(exception);
+    ASSERT_NOT_REACHED();
+}
+
 } // namespace DartNativeUtilitiesInternal
 
 namespace DartWindowInternal {
 
 void historyCrossFrameGetter(Dart_NativeArguments);
 
 void locationCrossFrameGetter(Dart_NativeArguments);
 
 }
 
@@ skipping 17 matching lines @@
     if (argumentCount == 1 && str == "Utils_forwardingPrint")
         return DartNativeUtilitiesInternal::forwardingPrint;
     if (argumentCount == 0 && str == "Utils_getNewIsolateId")
         return DartNativeUtilitiesInternal::getNewIsolateId;
     if (argumentCount == 4 && str == "Utils_register")
         return DartNativeUtilitiesInternal::registerElement;
     if (argumentCount == 2 && str == "Utils_createElement")
         return DartNativeUtilitiesInternal::createElement;
     if (argumentCount == 1 && str == "Utils_initializeCustomElement")
         return DartNativeUtilitiesInternal::initializeCustomElement;
+    if (argumentCount == 2 && str == "Utils_changeElementWrapper")
+        return DartNativeUtilitiesInternal::changeElementWrapper;
     if (argumentCount == 1 && str == "Utils_spawnDomUri")
         return DartNativeUtilitiesInternal::spawnDomUri;
     if (argumentCount == 1 && str == "Window_history_cross_frame_Getter")
         return DartWindowInternal::historyCrossFrameGetter;
     if (argumentCount == 1 && str == "Window_location_cross_frame_Getter")
         return DartWindowInternal::locationCrossFrameGetter;
     return 0;
 }
 
 }