Implement author-constructible ReadableStream using V8 extras

Implement author-constructible ReadableStream using V8 extras

This implements the ReadableStream and CountQueuingStrategy classes from the Streams Standard using V8 extras. They are marked experimental. The implementation follows the spec and reference implementation very closely.

The IDL implementation of ReadableStream is no longer exposed to the global scope; it was not usable in any way. But, to avoid any breakage in the interim, we introduce a non-experimental ReadableStreamTempStub.js V8 extra that replaces the IDL implementation with equivalent (non-)functionality.

Further work will be necessary to integrate this implementation with Fetch, replacing Fetch's use of ReadableByteStream, before we can completely remove the existing implementation. The current implementation landscape is explained in the new README.md file in this directory.

The tests are drawn from https://github.com/whatwg/streams/tree/master/reference-implementation/web-platform-tests.

BUG=503491
R=yhirano@chromium.org,jochen@chromium.org

Committed: https://crrev.com/5ba05470cb4c1faece2db12886b09148ef2456ee
Cr-Commit-Position: refs/heads/master@{#362201}

[domenic, 2015-10-13 23:01:00]

This is not quite ready to land but it is ready for review. After we have been
through some initial review I can add an OWNER reviewer for the gypi/gni
changes.

Depends on two V8 side changes for small issues I discovered:
- https://codereview.chromium.org/1400253002
- https://codereview.chromium.org/1401243003

This is the result of me updating https://codereview.chromium.org/1167343002,
and breaking it down into smaller CLs. It only implements the JS code, without
any C++ integration.

I am not sure my strategy of NoInterfaceObject for the existing ReadableStream
is the best idea. Especially since it would be web-visible when the experimental
flag is not flipped on. Suggestions welcome on how to work around that.

I should probably also add something like
https://codereview.chromium.org/1167343002/diff/210001/Source/core/streams/RE...

[yhirano, 2015-10-14 10:28:49]

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/LayoutTe...
File
third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/bad-strategies.js
(right):

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/bad-strategies.js:21:
test1.step(function() {
Can you use promise_test instead of async_test?
Ditto for others.

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/bad-strategies.js:94:
assert_throws(new RangeError(), function() { throw error; }, 'enqueue should
throw a RangeError for ' + elements[i]);
assert_equals(error.name, 'RangeError', ...);

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/streams/ReadableStream.js (right):

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/streams/ReadableStream.js:453: // TODO can we use
`in` instead of hasOwnProperty?
TODO(domenic):

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/streams/ReadableStream.js:576: stream) {  //
shouldClone argument from spec not supported yet
TODO(domenic):

[domenic, 2015-10-14 16:25:31]

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/LayoutTe...
File
third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/bad-strategies.js
(right):

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/bad-strategies.js:21:
test1.step(function() {
On 2015/10/14 at 10:28:49, yhirano wrote:
> Can you use promise_test instead of async_test?
> Ditto for others.

My intention in importing the tests was to not spend an inordinate amount of
time curating them. They are imported straight from WebKit more or less. I think
the payoff of converting them all to promise_test would be low.

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/LayoutTe...
third_party/WebKit/LayoutTests/http/tests/streams/readable-streams/bad-strategies.js:94:
assert_throws(new RangeError(), function() { throw error; }, 'enqueue should
throw a RangeError for ' + elements[i]);
On 2015/10/14 at 10:28:49, yhirano wrote:
> assert_equals(error.name, 'RangeError', ...);

done

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/Source/c...
File third_party/WebKit/Source/core/streams/ReadableStream.js (right):

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/streams/ReadableStream.js:453: // TODO can we use
`in` instead of hasOwnProperty?
On 2015/10/14 at 10:28:49, yhirano wrote:
> TODO(domenic):

Removed; I remembered why it was invalid to use `in`.

https://codereview.chromium.org/1404523005/diff/1/third_party/WebKit/Source/c...
third_party/WebKit/Source/core/streams/ReadableStream.js:576: stream) {  //
shouldClone argument from spec not supported yet
On 2015/10/14 at 10:28:49, yhirano wrote:
> TODO(domenic):

done

[domenic, 2015-10-14 22:07:44]

OK, after today's changes, I think this is ready to merge (when you are happy
with it).

[yhirano, 2015-10-15 06:04:40]

Hm, then what do you want me to do? Should I review tests in this CL, or review
tests on github?

Even if you use async_test, I generally prefer

async_test(function(t) {
  ...
}, description);

to

var testX = async_test(description);
testX.step(function() {
  ...
});

especially with many test cases because with the latter pattern it is very easy
to make test name mistakes.

[yhirano, 2015-10-15 08:04:55]

https://codereview.chromium.org/1404523005/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/streams/ReadableStream.idl (right):

https://codereview.chromium.org/1404523005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/streams/ReadableStream.idl:7: // streams, and so
we can't remove it quite yet.
Response.body (and Request.body) is currently of type ReadableByteStream.

[yhirano, 2015-10-15 08:07:13]

https://codereview.chromium.org/1404523005/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/streams/ReadableStream.idl (right):

https://codereview.chromium.org/1404523005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/streams/ReadableStream.idl:7: // streams, and so
we can't remove it quite yet.
On 2015/10/15 08:04:55, yhirano wrote:
> Response.body (and Request.body) is currently of type ReadableByteStream.

Oops, I thought I exposed Request.body experimentally but I was wrong. Please
never mind about Request.body.

[domenic, 2015-10-15 15:58:50]

On 2015/10/15 at 06:04:40, yhirano wrote:
> Hm, then what do you want me to do? Should I review tests in this CL, or
review tests on github?
> 
> Even if you use async_test, I generally prefer
> 
> async_test(function(t) {
>   ...
> }, description);
> 
> to
> 
> var testX = async_test(description);
> testX.step(function() {
>   ...
> });
> 
> especially with many test cases because with the latter pattern it is very
easy to make test name mistakes.

I agree the tests are not great in terms of style. However, I thought we would
be best off treating them like any other imported test (e.g. the ones in
imported/web-platform-tests). Those are written by a large variety of people
from other companies and we don't do in-depth reviews and style fixes on them
before we import them.

Alternately I can take the time to make the tests nicer, but it is a
time-consuming process, that IMO will not increase coverage.

[domenic, 2015-10-15 16:01:42]

https://codereview.chromium.org/1404523005/diff/80001/third_party/WebKit/Sour...
File third_party/WebKit/Source/core/streams/ReadableStream.idl (right):

https://codereview.chromium.org/1404523005/diff/80001/third_party/WebKit/Sour...
third_party/WebKit/Source/core/streams/ReadableStream.idl:7: // streams, and so
we can't remove it quite yet.
On 2015/10/15 at 08:07:13, yhirano wrote:
> On 2015/10/15 08:04:55, yhirano wrote:
> > Response.body (and Request.body) is currently of type ReadableByteStream.
> 
> Oops, I thought I exposed Request.body experimentally but I was wrong. Please
never mind about Request.body.

Yes, it is of type ReadableByteStream, but on the C++ side ReadableByteStream
inherits from ReadableStreamImpl which inherits from ReadableStream. So it is
still used and I don't think we can remove it.

[domenic, 2015-10-19 20:37:52]

Ping. What are my remaining action items? Do I need to change all the tests
before this can be merged? I am willing to do so if necessary.

[yhirano, 2015-10-20 01:38:15]

On 2015/10/19 20:37:52, domenic wrote:
> Ping. What are my remaining action items? Do I need to change all the tests
> before this can be merged? I am willing to do so if necessary.

https://codereview.chromium.org/1404523005/#msg5

I would like to know how to improve tests.

[domenic, 2015-10-20 02:01:56]

On 2015/10/20 at 01:38:15, yhirano wrote:
> On 2015/10/19 20:37:52, domenic wrote:
> > Ping. What are my remaining action items? Do I need to change all the tests
> > before this can be merged? I am willing to do so if necessary.
> 
> https://codereview.chromium.org/1404523005/#msg5
> 
> I would like to know how to improve tests.

OK. If it is not OK to just upstream the WebKit tests then you can review the
WebKit tests here and I will submit them back to WebKit. I will try to work on
the conversion from async_test to promise_test soon (but I am on vacation so it
might not be too fast). If there are other things let me know.

[yhirano, 2015-10-20 14:16:15]

On 2015/10/20 02:01:56, domenic wrote:
> On 2015/10/20 at 01:38:15, yhirano wrote:
> > On 2015/10/19 20:37:52, domenic wrote:
> > > Ping. What are my remaining action items? Do I need to change all the
tests
> > > before this can be merged? I am willing to do so if necessary.
> > 
> > https://codereview.chromium.org/1404523005/#msg5
> > 
> > I would like to know how to improve tests.
> 
> OK. If it is not OK to just upstream the WebKit tests then you can review the
> WebKit tests here and I will submit them back to WebKit. I will try to work on
> the conversion from async_test to promise_test soon (but I am on vacation so
it
> might not be too fast). If there are other things let me know.

I will propose PRs on the streams github repo.

[yhirano, 2015-10-21 03:45:26]

yhirano@chromium.org changed reviewers:
+ jochen@chromium.org

[yhirano, 2015-10-21 03:45:27]

+jochen

Jochen, should we write anything to import code and tests which are under cc0?
Is just using chromium license
enough?https://github.com/whatwg/streams/blob/master/reference-implementation/LICENSE.txt

https://codereview.chromium.org/1404523005/diff/100001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/streams/ReadableStream.js (right):

https://codereview.chromium.org/1404523005/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/streams/ReadableStream.js:1: (function(global,
binding, v8) {
LICENSE

[jochen (gone - plz use gerrit), 2015-11-02 19:06:07]

we can't use cc0 licensed stuff. please find a substitue or rewrite from scratch

[yhirano, 2015-11-04 10:31:11]

On 2015/11/02 19:06:07, jochen wrote:
> we can't use cc0 licensed stuff. please find a substitue or rewrite from
scratch

Thanks.

[domenic, 2015-11-11 21:56:08]

https://codereview.chromium.org/1404523005/diff/100001/third_party/WebKit/Sou...
File third_party/WebKit/Source/core/streams/ReadableStream.idl (right):

https://codereview.chromium.org/1404523005/diff/100001/third_party/WebKit/Sou...
third_party/WebKit/Source/core/streams/ReadableStream.idl:12: NoInterfaceObject
Probably a better idea: use Exposed=(Window FeatureThatIsV8ExtrasNegated, Worker
FeatureThatIsV8ExtrasNegated). And create such a feature. See last paragraph of
https://www.chromium.org/blink/webidl/blink-idl-extended-attributes#TOC-Expos...

Or an even better idea! Create a StableReadableStream.js V8 extra that is just
empty, and remove the IDL file.

[domenic, 2015-11-24 23:25:50]

Description was changed from

==========
Implement author-constructible ReadableStream using V8 extras

This implements the ReadableStream and CountQueuingStrategy classes from the
Streams Standard using V8 extras. They are marked experimental. The
implementation follows the spec and reference implementation very closely.

This disables the IDL-implemented ReadableStream class by marking it
NoInterfaceObject. After this patch, there will be three readable stream classes
in the system:

- This one, implemented in V8 extras, and exposed to the global scope
- The IDL-implemented one, not exposed to the global scope
- Another IDL-implemented class, ReadableByteStream, which is integrated with
Fetch and is also exposed to the global scope

Further work will be necessary to integrate this implementation with Fetch and
show that it can replace the two IDL-implemented classes.

The tests are drawn from https://github.com/whatwg/streams/pull/397 which are in
turn drawn from WebKit.

BUG=503491
R=yhirano@chromium.org,tyoshino@chromium.org
==========

to

==========
Implement author-constructible ReadableStream using V8 extras

This implements the ReadableStream and CountQueuingStrategy classes from the
Streams Standard using V8 extras. They are marked experimental. The
implementation follows the spec and reference implementation very closely.

The IDL implementation of ReadableStream is no longer exposed to the global
scope; it was not usable in any way. But, to avoid any breakage in the interim,
we introduce a non-experimental ReadableStreamTempStub.js V8 extra that replaces
the IDL implementation with equivalent (non-)functionality.

Further work will be necessary to integrate this implementation with Fetch,
replacing Fetch's use of ReadableByteStream, before we can completely remove the
existing implementation. The current implementation landscape is explained in
the new README.md file in this directory.

The tests are drawn from
https://github.com/whatwg/streams/tree/master/reference-implementation/web-pl....

BUG=503491
R=yhirano@chromium.org,tyoshino@chromium.org
==========

[domenic, 2015-11-24 23:28:47]

Tests have been updated to use promise_test throughout. (See changes at
https://github.com/whatwg/streams/pull/408.) Implementation strategy for
global.ReadableStream changed as discussed at BlinkOn, to eliminate
ReadableStream.idl.

PTAL.

[domenic, 2015-11-24 23:34:01]

On 2015/11/24 at 23:28:47, domenic wrote:
> Tests have been updated to use promise_test throughout. (See changes at
https://github.com/whatwg/streams/pull/408.) Implementation strategy for
global.ReadableStream changed as discussed at BlinkOn, to eliminate
ReadableStream.idl.
> 
> PTAL.

Oh, and the test licensing was changed so that we should be able to import them
without trouble.

[domenic, 2015-11-24 23:48:37]

The CQ bit was checked by domenic@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-11-24 23:51:02]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1404523005/120001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1404523005/120001

[commit-bot: I haz the power, 2015-11-24 23:51:03]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-11-24 23:51:04]

Dry run: No L-G-T-M from a valid reviewer yet. Only full committers are
accepted.
Even if an L-G-T-M may have been provided, it was from a non-committer,
_not_ a full super star committer.
See http://www.chromium.org/getting-involved/become-a-committer
Note that this has nothing to do with OWNERS files.

[yhirano, 2015-11-25 02:12:16]

On 2015/11/24 23:34:01, domenic wrote:
> On 2015/11/24 at 23:28:47, domenic wrote:
> > Tests have been updated to use promise_test throughout. (See changes at
> https://github.com/whatwg/streams/pull/408.) Implementation strategy for
> global.ReadableStream changed as discussed at BlinkOn, to eliminate
> ReadableStream.idl.
> > 
> > PTAL.
> 
> Oh, and the test licensing was changed so that we should be able to import
them
> without trouble.

Can you add license statement to each js file in Source/core/streams (like c++
files)?
If it's difficult, it may be OK to have a separate LICENSE file in the directory
(c.f. [1])

1:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

[domenic, 2015-11-25 16:00:45]

On 2015/11/25 at 02:12:16, yhirano wrote:
> On 2015/11/24 23:34:01, domenic wrote:
> > On 2015/11/24 at 23:28:47, domenic wrote:
> > > Tests have been updated to use promise_test throughout. (See changes at
> > https://github.com/whatwg/streams/pull/408.) Implementation strategy for
> > global.ReadableStream changed as discussed at BlinkOn, to eliminate
> > ReadableStream.idl.
> > > 
> > > PTAL.
> > 
> > Oh, and the test licensing was changed so that we should be able to import
them
> > without trouble.
> 
> Can you add license statement to each js file in Source/core/streams (like c++
files)?
> If it's difficult, it may be OK to have a separate LICENSE file in the
directory (c.f. [1])
> 
> 1:
https://code.google.com/p/chromium/codesearch#chromium/src/third_party/WebKit...

Done. Since these are original source code only based on the reference
implementation, but not a copy of it, I just added the standard Chromium block.
(They have fairly substantial divergences to fit with V8 extras, and to be more
performant.)

[yhirano, 2015-11-25 16:08:46]

lgtm

[domenic, 2015-11-25 16:09:52]

The CQ bit was checked by domenic@chromium.org

[commit-bot: I haz the power, 2015-11-25 16:11:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1404523005/140001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1404523005/140001

[commit-bot: I haz the power, 2015-11-25 16:14:39]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-11-25 16:14:40]

Try jobs failed on following builders:
  cast_shell_android on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/cast_shell_andr...)
  cast_shell_linux on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/cast_shell_linu...)
  chromeos_daisy_chromium_compile_only_ng on tryserver.chromium.linux
(JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromeos_daisy_...)
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)
  linux_chromium_chromeos_compile_dbg_ng on tryserver.chromium.linux
(JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_chromeos_ozone_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_chromeos_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_clobber_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_compile_dbg_32_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  linux_chromium_compile_dbg_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)
  mac_chromium_compile_dbg_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)
  win8_chromium_ng on tryserver.chromium.win (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_ng/...)

[domenic, 2015-11-25 17:29:11]

The CQ bit was checked by domenic@chromium.org

[domenic, 2015-11-25 17:29:11]

The patchset sent to the CQ was uploaded after l-g-t-m from yhirano@chromium.org
Link to the patchset: https://codereview.chromium.org/1404523005/#ps160001
(title: "Rebase")

[commit-bot: I haz the power, 2015-11-25 17:29:43]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1404523005/160001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1404523005/160001

[commit-bot: I haz the power, 2015-11-25 17:41:32]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-11-25 17:41:33]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[domenic, 2015-11-25 17:41:55]

On 2015/11/25 at 17:29:43, commit-bot wrote:
> CQ is trying da patch. Follow status at
>  https://chromium-cq-status.appspot.com/patch-status/1404523005/160001
> View timeline at
>  https://chromium-cq-status.appspot.com/patch-timeline/1404523005/160001

jochen, can I get a new l-g-t-m for

build/common.gypi
build_overrides/v8.gni
third_party/WebKit/Source/core/core.gypi

?

[domenic, 2015-11-25 17:46:44]

Description was changed from

==========
Implement author-constructible ReadableStream using V8 extras

This implements the ReadableStream and CountQueuingStrategy classes from the
Streams Standard using V8 extras. They are marked experimental. The
implementation follows the spec and reference implementation very closely.

The IDL implementation of ReadableStream is no longer exposed to the global
scope; it was not usable in any way. But, to avoid any breakage in the interim,
we introduce a non-experimental ReadableStreamTempStub.js V8 extra that replaces
the IDL implementation with equivalent (non-)functionality.

Further work will be necessary to integrate this implementation with Fetch,
replacing Fetch's use of ReadableByteStream, before we can completely remove the
existing implementation. The current implementation landscape is explained in
the new README.md file in this directory.

The tests are drawn from
https://github.com/whatwg/streams/tree/master/reference-implementation/web-pl....

BUG=503491
R=yhirano@chromium.org,tyoshino@chromium.org
==========

to

==========
Implement author-constructible ReadableStream using V8 extras

This implements the ReadableStream and CountQueuingStrategy classes from the
Streams Standard using V8 extras. They are marked experimental. The
implementation follows the spec and reference implementation very closely.

The IDL implementation of ReadableStream is no longer exposed to the global
scope; it was not usable in any way. But, to avoid any breakage in the interim,
we introduce a non-experimental ReadableStreamTempStub.js V8 extra that replaces
the IDL implementation with equivalent (non-)functionality.

Further work will be necessary to integrate this implementation with Fetch,
replacing Fetch's use of ReadableByteStream, before we can completely remove the
existing implementation. The current implementation landscape is explained in
the new README.md file in this directory.

The tests are drawn from
https://github.com/whatwg/streams/tree/master/reference-implementation/web-pl....

BUG=503491
R=yhirano@chromium.org,jochen@chromium.org
==========

[jochen (gone - plz use gerrit), 2015-11-26 13:22:32]

lgtm

[domenic, 2015-11-30 18:27:41]

The CQ bit was checked by domenic@chromium.org

[domenic, 2015-11-30 18:27:41]

The patchset sent to the CQ was uploaded after l-g-t-m from
yhirano@chromium.org, jochen@chromium.org
Link to the patchset: https://codereview.chromium.org/1404523005/#ps240001
(title: "Minor test tweaks")

[commit-bot: I haz the power, 2015-11-30 18:28:19]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1404523005/240001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1404523005/240001

[commit-bot: I haz the power, 2015-11-30 20:09:47]

Committed patchset #13 (id:240001)

[commit-bot: I haz the power, 2015-11-30 20:10:54]

Description was changed from

==========
Implement author-constructible ReadableStream using V8 extras

This implements the ReadableStream and CountQueuingStrategy classes from the
Streams Standard using V8 extras. They are marked experimental. The
implementation follows the spec and reference implementation very closely.

The IDL implementation of ReadableStream is no longer exposed to the global
scope; it was not usable in any way. But, to avoid any breakage in the interim,
we introduce a non-experimental ReadableStreamTempStub.js V8 extra that replaces
the IDL implementation with equivalent (non-)functionality.

Further work will be necessary to integrate this implementation with Fetch,
replacing Fetch's use of ReadableByteStream, before we can completely remove the
existing implementation. The current implementation landscape is explained in
the new README.md file in this directory.

The tests are drawn from
https://github.com/whatwg/streams/tree/master/reference-implementation/web-pl....

BUG=503491
R=yhirano@chromium.org,jochen@chromium.org
==========

to

==========
Implement author-constructible ReadableStream using V8 extras

This implements the ReadableStream and CountQueuingStrategy classes from the
Streams Standard using V8 extras. They are marked experimental. The
implementation follows the spec and reference implementation very closely.

The IDL implementation of ReadableStream is no longer exposed to the global
scope; it was not usable in any way. But, to avoid any breakage in the interim,
we introduce a non-experimental ReadableStreamTempStub.js V8 extra that replaces
the IDL implementation with equivalent (non-)functionality.

Further work will be necessary to integrate this implementation with Fetch,
replacing Fetch's use of ReadableByteStream, before we can completely remove the
existing implementation. The current implementation landscape is explained in
the new README.md file in this directory.

The tests are drawn from
https://github.com/whatwg/streams/tree/master/reference-implementation/web-pl....

BUG=503491
R=yhirano@chromium.org,jochen@chromium.org

Committed: https://crrev.com/5ba05470cb4c1faece2db12886b09148ef2456ee
Cr-Commit-Position: refs/heads/master@{#362201}
==========

[commit-bot: I haz the power, 2015-11-30 20:10:55]

Patchset 13 (id:??) landed as
https://crrev.com/5ba05470cb4c1faece2db12886b09148ef2456ee
Cr-Commit-Position: refs/heads/master@{#362201}