Use Dart_InstanceIsSubtypeOf to check if instance is a direct subtype of specified type.

Use Dart_InstanceIsSubtypeOf to check if instance is a direct subtype of specified type.

Improves couple of dromaeo benchmarks:
dom-modify appendChild runs-per-second from 882.0 to 1373.0
dom-modify insertBefore runs-per-second from 589.0 to 1111.0

[vsm, 2013-10-14 15:44:09]

https://chromiumcodereview.appspot.com/27140002/diff/1/Source/bindings/dart/D...
File Source/bindings/dart/DartDOMWrapper.h (left):

https://chromiumcodereview.appspot.com/27140002/diff/1/Source/bindings/dart/D...
Source/bindings/dart/DartDOMWrapper.h:171: Dart_Handle result =
Dart_ObjectIsType(wrapper, type, &isInstanceOf);
Siva: Just curious, what's the semantic difference between ObjectIsType and
InstanceIsSubtypeOf?  Why is the latter more efficient?

[siva, 2013-10-14 15:55:05]

https://chromiumcodereview.appspot.com/27140002/diff/1/Source/bindings/dart/D...
File Source/bindings/dart/DartDOMWrapper.h (left):

https://chromiumcodereview.appspot.com/27140002/diff/1/Source/bindings/dart/D...
Source/bindings/dart/DartDOMWrapper.h:171: Dart_Handle result =
Dart_ObjectIsType(wrapper, type, &isInstanceOf);
Dart_InstanceIsSubtypeOf just does a straight sub class check without looking
into interfaces etc. It also only deals with non parameterized types which is
what all these Web native types are.
(This will also take care of the issue 11008).

On 2013/10/14 15:44:09, vsm wrote:
> Siva: Just curious, what's the semantic difference between ObjectIsType and
> InstanceIsSubtypeOf?  Why is the latter more efficient?

[vsm, 2013-10-14 15:58:11]

Thanks - lgtm!

You may want to consider renaming Dart_InstanceIsSubtypeOf though - the
different semantics are not clear from the name.  E.g., Subclass instead of
Subtype?  Gilad might have some ideas.

[rmacnak, 2013-10-14 17:36:19]

On 2013/10/14 15:58:11, vsm wrote:
> Thanks - lgtm!
> 
> You may want to consider renaming Dart_InstanceIsSubtypeOf though - the
> different semantics are not clear from the name.  E.g., Subclass instead of
> Subtype?  Gilad might have some ideas.

Ditto on not including "type" in the name because it ignores type arguments and
interfaces. Dart_IsInstanceOfSubclassOf describes exactly what the test does.

[rmacnak, 2013-10-14 17:37:26]

https://codereview.chromium.org/27140002/diff/1/Source/bindings/dart/DartUtil...
File Source/bindings/dart/DartUtilities.cpp (right):

https://codereview.chromium.org/27140002/diff/1/Source/bindings/dart/DartUtil...
Source/bindings/dart/DartUtilities.cpp:354: return objectIsType(handle, type);
Should we be using the new test here too?

[siva, 2013-10-15 17:09:07]

After some discussion with Regis about a proper name for this new API function I
came to the conclusion that this API function doesn't quite gel with Dart
semantics and seems like the wrong way to go about doing things.

I am closing this CL and will upload a new set of CLs which use the native class
hierarchy to do this subtype of check.