[build] Fix race in v8gen

[build] Fix race in v8gen

BUG=chromium:648583
NOTRY=true

Committed: https://crrev.com/6cd5d73c6c790a59f9e6a78a9c83b7db83ba4dec
Cr-Commit-Position: refs/heads/master@{#39626}

[Michael Achenbach, 2016-09-22 09:06:07]

Description was changed from

==========
[build] Fix race in v8gen

BUG=
==========

to

==========
[build] Fix race in v8gen

BUG=chromium:648583
==========

[Michael Achenbach, 2016-09-22 09:06:07]

machenbach@chromium.org changed reviewers:
+ jochen@chromium.org, vogelheim@chromium.org

[Michael Achenbach, 2016-09-22 09:08:28]

PTAL

https://codereview.chromium.org/2365573002/diff/20001/tools/dev/v8gen.py
File tools/dev/v8gen.py (right):

https://codereview.chromium.org/2365573002/diff/20001/tools/dev/v8gen.py#newc...
tools/dev/v8gen.py:271: mtime = os.path.getmtime(gn_args_path) + 1
Really needs + 1, smaller increments don't trigger a rebuild. We also need to
open the file once more. Adding this logic to the open block above, doesn't lead
to the desired result either.

[Michael Achenbach, 2016-09-22 09:08:35]

Description was changed from

==========
[build] Fix race in v8gen

BUG=chromium:648583
==========

to

==========
[build] Fix race in v8gen

BUG=chromium:648583
NOTRY=true
==========

[jochen (gone - plz use gerrit), 2016-09-22 13:22:16]

lgtm

[Michael Achenbach, 2016-09-22 13:29:01]

The CQ bit was checked by machenbach@chromium.org

[commit-bot: I haz the power, 2016-09-22 13:29:11]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-09-22 13:31:32]

Description was changed from

==========
[build] Fix race in v8gen

BUG=chromium:648583
NOTRY=true
==========

to

==========
[build] Fix race in v8gen

BUG=chromium:648583
NOTRY=true
==========

[commit-bot: I haz the power, 2016-09-22 13:31:33]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2016-09-22 13:31:51]

Description was changed from

==========
[build] Fix race in v8gen

BUG=chromium:648583
NOTRY=true
==========

to

==========
[build] Fix race in v8gen

BUG=chromium:648583
NOTRY=true

Committed: https://crrev.com/6cd5d73c6c790a59f9e6a78a9c83b7db83ba4dec
Cr-Commit-Position: refs/heads/master@{#39626}
==========

[commit-bot: I haz the power, 2016-09-22 13:31:52]

Patchset 2 (id:??) landed as
https://crrev.com/6cd5d73c6c790a59f9e6a78a9c83b7db83ba4dec
Cr-Commit-Position: refs/heads/master@{#39626}