Add GN build support for Android 64-bit platforms.

Add GN build support for Android 64-bit platforms.

gn now run with arg target_arch = "x64", arm64 and mips64el
releated changes are added as well but not verified.

BUG=none

Committed: https://crrev.com/98de73d11797b1b0ac7ac0b2f4234cb8f57bd2fc
Cr-Commit-Position: refs/heads/master@{#315680}

[haltonhuo, 2015-02-09 09:17:00]

halton.huo@intel.com changed reviewers:
+ blundell@chromium.org, brettw@chromium.org, qsr@chromium.org

[haltonhuo, 2015-02-09 09:17:01]

This CL is original submitted for mojo project, but truns out I should do in
chromium instead. Please review.

[qsr, 2015-02-09 09:35:27]

Remove mojob comment in the description. This is a mojo specific tool.

[haltonhuo, 2015-02-09 09:40:37]

On 2015/02/09 09:35:27, qsr wrote:
> Remove mojob comment in the description. This is a mojo specific tool.

Done in set 2

[qsr, 2015-02-09 09:47:20]

LGTM

[haltonhuo, 2015-02-09 09:47:54]

The CQ bit was checked by halton.huo@intel.com

[commit-bot: I haz the power, 2015-02-09 09:49:12]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/864173006/20001

[qsr, 2015-02-09 09:51:20]

On 2015/02/09 09:49:12, I haz the power (commit-bot) wrote:
> CQ is trying da patch. Follow status at
>  https://chromium-cq-status.appspot.com/patch-status/864173006/20001

I'm not an owner of those files, you need Brett LGTM.

[haltonhuo, 2015-02-09 09:53:04]

On 2015/02/09 09:51:20, qsr wrote:
> On 2015/02/09 09:49:12, I haz the power (commit-bot) wrote:
> > CQ is trying da patch. Follow status at
> >  https://chromium-cq-status.appspot.com/patch-status/864173006/20001
> 
> I'm not an owner of those files, you need Brett LGTM.

Ah, sorry, I just unchecked the checkbox? Will that stopped commit trying?

[haltonhuo, 2015-02-09 09:53:09]

The CQ bit was unchecked by halton.huo@intel.com

[qsr, 2015-02-09 09:54:32]

On 2015/02/09 09:53:04, haltonhuo wrote:
> On 2015/02/09 09:51:20, qsr wrote:
> > On 2015/02/09 09:49:12, I haz the power (commit-bot) wrote:
> > > CQ is trying da patch. Follow status at
> > >  https://chromium-cq-status.appspot.com/patch-status/864173006/20001
> > 
> > I'm not an owner of those files, you need Brett LGTM.
> 
> Ah, sorry, I just unchecked the checkbox? Will that stopped commit trying?

It will. But the commit queue would have rejected the change anyway.

[brettw, 2015-02-10 22:52:28]

lgtm

[haltonhuo, 2015-02-11 00:02:15]

The CQ bit was checked by halton.huo@intel.com

[commit-bot: I haz the power, 2015-02-11 00:02:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/864173006/20001

[commit-bot: I haz the power, 2015-02-11 00:08:40]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-11 00:09:27]

Patchset 2 (id:??) landed as
https://crrev.com/98de73d11797b1b0ac7ac0b2f4234cb8f57bd2fc
Cr-Commit-Position: refs/heads/master@{#315680}