Revert of Revert of Add d8 target to the GN build.

Revert of Revert of Add d8 target to the GN build. (patchset #1 id:1 of https://codereview.chromium.org/838983002/)

Reason for revert:
Relanding because this is not actually blocking the roll.

Original issue's description:
> Revert of Add d8 target to the GN build. (patchset #2 id:40001 of https://codereview.chromium.org/834113005/)
>
> Reason for revert:
> V8 roll fails due to this change. (see https://codereview.chromium.org/843673003/)
>
> Original issue's description:
> > Add d8 target to the GN build.
> >
> > Also formats the rest of the file with "gn format". This accounts for all the changes except for the "d8" target additions.
> >
> > Committed: https://crrev.com/36383f08c1f692ea797d54a27d7c6b3d3d53b440
> > Cr-Commit-Position: refs/heads/master@{#25984}
>
> TBR=jochen@chromium.org,machenbach@chromium.org,brettw@chromium.org
> NOTREECHECKS=true
> NOTRY=true
>
> Committed: https://crrev.com/ef50fdfdb05e1a3a3822962f5235b804218a5f4e
> Cr-Commit-Position: refs/heads/master@{#25985}

TBR=jochen@chromium.org,machenbach@chromium.org,brettw@chromium.org
NOTREECHECKS=true
NOTRY=true

Committed: https://crrev.com/ebf3c34fb91b4b61f5c32383a115214c516ab5b0
Cr-Commit-Position: refs/heads/master@{#25996}

[Yang, 2015-01-08 13:21:03]

Created Revert of Revert of Add d8 target to the GN build.

[commit-bot: I haz the power, 2015-01-08 13:21:50]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/833563004/1

[commit-bot: I haz the power, 2015-01-08 13:21:58]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-08 13:22:13]

Patchset 1 (id:??) landed as
https://crrev.com/ebf3c34fb91b4b61f5c32383a115214c516ab5b0
Cr-Commit-Position: refs/heads/master@{#25996}

[brettw, 2015-01-09 02:24:16]

Thanks! I was pretty mystified about the error...

[Michael Achenbach, 2015-01-14 11:17:05]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/792903005/ by machenbach@chromium.org.

The reason for reverting is: This is now really blocking the roll (I guess). V8
was reverted because of this:
http://build.chromium.org/p/chromium.win/builders/Win8%20GN%20%28dbg%29/build....

[dcarney, 2015-01-14 11:50:48]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/810493004/ by dcarney@chromium.org.

The reason for reverting is: This is now really blocking the roll.  I believe
it's just missing 

    configs -= [ "//build/config/compiler:chromium_code" ]
    configs += [ "//build/config/compiler:no_chromium_code" ]

in the d8 config but I have no way to check..

[Michael Achenbach, 2015-01-14 21:10:04]

This is odd. The roll right after this revert got through and stayed. Now I
tried a newer roll and got similar errors again on this new trybot:
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_gn_...

The bot also failed earlier with the same error on a white space CL:
https://codereview.chromium.org/821353005/

Maybe this should be investigated by the owners of the bot.

[Michael Achenbach, 2015-01-14 21:20:12]

machenbach@chromium.org changed reviewers:
+ dpranke@chromium.org, scottmg@chromium.org

[Michael Achenbach, 2015-01-14 21:20:12]

+ dpranke and scottmg regarding the reliability of the win8 gn trybot. How could
this happen:
https://codereview.chromium.org/821353005/

Is something wrong with the incremental build?

[Dirk Pranke, 2015-01-14 21:23:07]

On 2015/01/14 21:20:12, Michael Achenbach wrote:
> + dpranke and scottmg regarding the reliability of the win8 gn trybot. How
could
> this happen:
> https://codereview.chromium.org/821353005/
> 
> Is something wrong with the incremental build?

It looks like the GN build was broken at tip-of-tree around the same time.

http://build.chromium.org/p/chromium.win/builders/Win8%20GN?numbuilds=100
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_gn_rel

I think this failure is probably correct.

[Dirk Pranke, 2015-01-14 21:38:01]

On 2015/01/14 21:23:07, Dirk Pranke wrote:
> On 2015/01/14 21:20:12, Michael Achenbach wrote:
> > + dpranke and scottmg regarding the reliability of the win8 gn trybot. How
> could
> > this happen:
> > https://codereview.chromium.org/821353005/
> > 
> > Is something wrong with the incremental build?
> 
> It looks like the GN build was broken at tip-of-tree around the same time.
> 
> http://build.chromium.org/p/chromium.win/builders/Win8%20GN?numbuilds=100
>
http://build.chromium.org/p/tryserver.chromium.win/builders/win8_chromium_gn_rel
> 
> I think this failure is probably correct.

Here's a bit more info (since I'm not sure exactly what you were asking): the
failure at tip-of-tree looks like it was caused by the v8 autoroll (which you
probably already know).

*That* change -- https://codereview.chromium.org/847343002 -- did not run the
win8 GN bot, because that bot is not currently part of the CQ. So, this sort of
failure was predictable (though rare).

I'm currently in the middle of adding the Mac, Win, and ChromeOS GN bots to the
commit queue -- crbug.com/439402 -- to prevent this problem from happening in
the future.