[runtime] We don't need an actual instance type for JSIteratorResult.

[runtime] We don't need an actual instance type for JSIteratorResult.

It's fine to use JS_OBJECT_TYPE for JSIteratorResult and only have a
preallocated initial map for them to avoid unnecessary polymorphism
from generators / builtin iterators. The instance type doesn't
provide any advantage, since we always have to treat JSIteratorResult
objects as regular JSObjects later.

R=yangguo@chromium.org
TBR=hpayer@chromium.org

Committed: https://crrev.com/f3b0dbb5e794aed871e4e6167016b371f70680e8
Cr-Commit-Position: refs/heads/master@{#33800}

[Benedikt Meurer, 2016-02-06 18:03:52]

Hey Yang,

I just figured out that the instance type is completely unnecessary and that the
initial map is enough to get all the benefits. So keeping number of specialized
JSObject instance types to the bare minimum.
Please take a look.

Thanks,
Benedikt

TBR'd Hannes for the oneline change in objects-visiting.cc

[Yang, 2016-02-08 06:27:13]

lgtm. nice clean up.

https://codereview.chromium.org/1680513002/diff/1/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/1680513002/diff/1/src/objects.h#newcode2603
src/objects.h:2603: class JSIteratorResult: public JSObject {
do we want to keep the "final" keyword here?

[Benedikt Meurer, 2016-02-08 06:28:22]

https://codereview.chromium.org/1680513002/diff/1/src/objects.h
File src/objects.h (right):

https://codereview.chromium.org/1680513002/diff/1/src/objects.h#newcode2603
src/objects.h:2603: class JSIteratorResult: public JSObject {
On 2016/02/08 06:27:13, Yang wrote:
> do we want to keep the "final" keyword here?

Style fix :-)

[Benedikt Meurer, 2016-02-08 06:28:29]

The CQ bit was checked by bmeurer@chromium.org

[commit-bot: I haz the power, 2016-02-08 06:28:33]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1680513002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1680513002/1

[commit-bot: I haz the power, 2016-02-08 06:55:24]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-08 06:55:55]

Description was changed from

==========
[runtime] We don't need an actual instance type for JSIteratorResult.

It's fine to use JS_OBJECT_TYPE for JSIteratorResult and only have a
preallocated initial map for them to avoid unnecessary polymorphism
from generators / builtin iterators. The instance type doesn't
provide any advantage, since we always have to treat JSIteratorResult
objects as regular JSObjects later.

R=yangguo@chromium.org
TBR=hpayer@chromium.org
==========

to

==========
[runtime] We don't need an actual instance type for JSIteratorResult.

It's fine to use JS_OBJECT_TYPE for JSIteratorResult and only have a
preallocated initial map for them to avoid unnecessary polymorphism
from generators / builtin iterators. The instance type doesn't
provide any advantage, since we always have to treat JSIteratorResult
objects as regular JSObjects later.

R=yangguo@chromium.org
TBR=hpayer@chromium.org

Committed: https://crrev.com/f3b0dbb5e794aed871e4e6167016b371f70680e8
Cr-Commit-Position: refs/heads/master@{#33800}
==========

[commit-bot: I haz the power, 2016-02-08 06:55:56]

Patchset 1 (id:??) landed as
https://crrev.com/f3b0dbb5e794aed871e4e6167016b371f70680e8
Cr-Commit-Position: refs/heads/master@{#33800}