Add WeakMap to v8.h

Add WeakMap to v8.h

A new map wich references its keys weakly is added to v8.h. Internally it uses the same storage as JSWeakMap but doesn't depend on the JavaScript part of WeakMap implementation in weak-collection.js, hence it can be instantiated without entering any context.

BUG=chromium:437416
LOG=Y

Committed: https://crrev.com/37d4c57630636f21e3add8d3d1c7c978ff5fc8e0
Cr-Commit-Position: refs/heads/master@{#26401}

[yurys, 2015-01-28 17:40:39]

yurys@chromium.org changed reviewers:
+ aandrey@chromium.org, jochen@chromium.org, kozyatinskiy@chromium.org

[jochen (gone - plz use gerrit), 2015-01-28 18:59:21]

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

[jochen (gone - plz use gerrit), 2015-01-28 18:59:21]

generally looks good.

Add mstarzinger@ as weakmap expert

[yurys, 2015-01-30 08:12:06]

yurys@chromium.org changed reviewers:
- aandrey@chromium.org, kozyatinskiy@chromium.org

[yurys, 2015-02-02 10:40:33]

Michael, can you take a look?

[Michael Starzinger, 2015-02-03 13:21:55]

LGTM, just nits. Sorry for delay, this somehow dropped off my radar.

https://codereview.chromium.org/886473005/diff/1/include/v8.h
File include/v8.h (right):

https://codereview.chromium.org/886473005/diff/1/include/v8.h#newcode1533
include/v8.h:1533: * can be created without entering a v8::Context.
nit: Can we add "... and hence shouldn't escape to JavaScript" to the comment
just to drive home the point?

https://codereview.chromium.org/886473005/diff/1/include/v8.h#newcode1549
include/v8.h:1549: WeakMap(WeakMap&);
nit: // Disallow copying and assigning.

https://codereview.chromium.org/886473005/diff/1/src/api.cc
File src/api.cc (right):

https://codereview.chromium.org/886473005/diff/1/src/api.cc#newcode2242
src/api.cc:2242: 
nit: // --- W e a k M a p ---

https://codereview.chromium.org/886473005/diff/1/src/runtime/runtime-collecti...
File src/runtime/runtime-collections.cc (left):

https://codereview.chromium.org/886473005/diff/1/src/runtime/runtime-collecti...
src/runtime/runtime-collections.cc:419: // strong root list.
Can we preserve an adapted version of this TODO within Factory::NewJSWeakMap?

[yurys, 2015-02-03 13:39:07]

https://codereview.chromium.org/886473005/diff/1/include/v8.h
File include/v8.h (right):

https://codereview.chromium.org/886473005/diff/1/include/v8.h#newcode1533
include/v8.h:1533: * can be created without entering a v8::Context.
On 2015/02/03 13:21:54, Michael Starzinger wrote:
> nit: Can we add "... and hence shouldn't escape to JavaScript" to the comment
> just to drive home the point?

Absolutely. Done.

https://codereview.chromium.org/886473005/diff/1/include/v8.h#newcode1549
include/v8.h:1549: WeakMap(WeakMap&);
On 2015/02/03 13:21:54, Michael Starzinger wrote:
> nit: // Disallow copying and assigning.

Done.

https://codereview.chromium.org/886473005/diff/1/src/api.cc
File src/api.cc (right):

https://codereview.chromium.org/886473005/diff/1/src/api.cc#newcode2242
src/api.cc:2242: 
On 2015/02/03 13:21:54, Michael Starzinger wrote:
> nit: // --- W e a k M a p ---

Done.

https://codereview.chromium.org/886473005/diff/1/src/runtime/runtime-collecti...
File src/runtime/runtime-collections.cc (left):

https://codereview.chromium.org/886473005/diff/1/src/runtime/runtime-collecti...
src/runtime/runtime-collections.cc:419: // strong root list.
On 2015/02/03 13:21:54, Michael Starzinger wrote:
> Can we preserve an adapted version of this TODO within Factory::NewJSWeakMap?

Done.

[yurys, 2015-02-03 13:39:10]

The CQ bit was checked by yurys@chromium.org

[commit-bot: I haz the power, 2015-02-03 13:39:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/886473005/20001

[commit-bot: I haz the power, 2015-02-03 13:44:25]

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

[commit-bot: I haz the power, 2015-02-03 13:44:26]

Try jobs failed on following builders:
  v8_linux64_rel on tryserver.v8
(http://build.chromium.org/p/tryserver.v8/builders/v8_linux64_rel/builds/2615)

[yurys, 2015-02-03 14:02:48]

The CQ bit was checked by yurys@chromium.org

[commit-bot: I haz the power, 2015-02-03 14:03:45]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/886473005/40001

[commit-bot: I haz the power, 2015-02-03 14:28:10]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-02-03 14:28:31]

Patchset 3 (id:??) landed as
https://crrev.com/37d4c57630636f21e3add8d3d1c7c978ff5fc8e0
Cr-Commit-Position: refs/heads/master@{#26401}

[vogelheim, 2015-02-03 14:41:25]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/875113004/ by vogelheim@chromium.org.

The reason for reverting is: Breaks Win32 build bot..

[yurys, 2015-02-03 14:41:29]

A revert of this CL (patchset #3 id:40001) has been created in
https://codereview.chromium.org/898763002/ by yurys@chromium.org.

The reason for reverting is: Broke compilation on component build
http://build.chromium.org/p/client.v8/builders/V8%20Win32%20-%20nosnap%20-%20....

[rossberg, 2015-02-03 17:09:20]

rossberg@chromium.org changed reviewers:
+ rossberg@chromium.org

[rossberg, 2015-02-03 17:09:21]

NOT LGTM. Please do not clobber the name of ES6's official WeakMap class (which
we will want to expose to the API eventually) for something different. That
would be highly confusing.

[yurys, 2015-02-04 07:24:51]

On 2015/02/03 17:09:21, rossberg wrote:
> NOT LGTM. Please do not clobber the name of ES6's official WeakMap class
(which
> we will want to expose to the API eventually) for something different. That
> would be highly confusing.

Any recommendations on the name? Would it be OK to call it WeakKeyMap?