Remove support for externally backed elements from the API

Remove support for externally backed elements from the API

Embedders should use ArrayBuffers instead

BUG=v8:3996
LOG=y
R=verwaest@chromium.org,dslomov@chromium.org,kbr@chromium.org

Committed: https://crrev.com/53cc6486df3e787898294664c0991f00ce57dcef
Cr-Commit-Position: refs/heads/master@{#27939}

[jochen (gone - plz use gerrit), 2015-04-17 11:31:31]

ptal

depends on https://codereview.chromium.org/1095823002

[Toon Verwaest, 2015-04-17 12:38:57]

lgtm

[Dmitry Lomov (no reviews), 2015-04-17 13:58:58]

this is probably quite problematic for io.js/node.js

[noordhuis, 2015-04-17 14:07:38]

This completely will completely break io.js and node.js and a great many
add-ons.

Saying embedders should use ArrayBuffer is easy but there is a whole ecosystem
built around the external array API and this change will have a disproportional
impact on that; the churn is going to be enormous.  I don't think this CL should
land.

[jochen (gone - plz use gerrit), 2015-04-17 14:29:18]

On 2015/04/17 at 14:07:38, info wrote:
> This completely will completely break io.js and node.js and a great many
add-ons.
> 
> Saying embedders should use ArrayBuffer is easy but there is a whole ecosystem
built around the external array API and this change will have a disproportional
impact on that; the churn is going to be enormous.  I don't think this CL should
land.

the only way going forward we could support this API is by completely
duplicating the current code, as the array buffer code is changing in a way
incompatible with this API.

otoh, I don't think it's going to be so much more worse than all the changes to
our handle API...

... anyway. I'll bring this up for discussion, but don't get your hopes up just
yet

[jochen (gone - plz use gerrit), 2015-04-20 11:12:34]

We decided to move forward with this. The actual change is that now only types
inheriting from ArrayBufferView (typed arrays and DataView) can have externally
backed elements. All other functionality should still be present and I'll add
missing APIs if io.js/node.js runs into problems.

[jochen (gone - plz use gerrit), 2015-04-20 11:12:38]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2015-04-20 11:12:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1092923002/1

[commit-bot: I haz the power, 2015-04-20 11:54:57]

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

[commit-bot: I haz the power, 2015-04-20 11:54:58]

Try jobs failed on following builders:
  v8_linux64_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_rel/builds/5017)

[jochen (gone - plz use gerrit), 2015-04-20 12:03:32]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2015-04-20 12:03:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1092923002/1

[commit-bot: I haz the power, 2015-04-20 12:34:48]

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

[commit-bot: I haz the power, 2015-04-20 12:34:48]

Try jobs failed on following builders:
  v8_linux_arm64_rel on tryserver.v8 (JOB_FAILED,
http://build.chromium.org/p/tryserver.v8/builders/v8_linux_arm64_rel/builds/4935)

[jochen (gone - plz use gerrit), 2015-04-20 12:35:11]

The CQ bit was checked by jochen@chromium.org

[commit-bot: I haz the power, 2015-04-20 12:35:27]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1092923002/1

[commit-bot: I haz the power, 2015-04-20 13:31:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-20 13:31:56]

Patchset 1 (id:??) landed as
https://crrev.com/53cc6486df3e787898294664c0991f00ce57dcef
Cr-Commit-Position: refs/heads/master@{#27939}