GN: Build //base with USE_SYMBOLIZE on Linux

GN: Build //base with USE_SYMBOLIZE on Linux

In base.gyp, USE_SYMBOLIZE is added for Desktop Linux and
Chrome OS builds for both base and base_unittests. In the GN
build, it's added for 'is_linux' builds (which does not include
Android), but only for base_unittests. This adds the define for
//base as well.

BUG=335824
TEST=build base and base_unittests, make a debug build and force a DCHECK() -- you should get a useful stack trace
R=scottmg@chromium.org

Committed: https://crrev.com/f324157fb51248250b91a87cd3d30a8928b79077
Cr-Commit-Position: refs/heads/master@{#295885}

[Chris Masone, 2014-09-20 00:50:43]

PTAL

[scottmg, 2014-09-20 02:11:36]

lgtm

[Chris Masone, 2014-09-20 02:13:49]

The CQ bit was checked by cmasone@chromium.org

[commit-bot: I haz the power, 2014-09-20 02:14:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/583263003/1

[commit-bot: I haz the power, 2014-09-20 02:31:07]

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

[commit-bot: I haz the power, 2014-09-20 02:31:08]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[scottmg, 2014-09-20 06:01:26]

scottmg@chromium.org changed reviewers:
+ brettw@chromium.org

[scottmg, 2014-09-20 06:01:27]

+brettw owners

[brettw, 2014-09-20 06:02:32]

lgtm

[Chris Masone, 2014-09-20 19:09:47]

On 2014/09/20 06:02:32, brettw wrote:
> lgtm

Ah, thanks!

[Chris Masone, 2014-09-20 19:09:51]

The CQ bit was checked by cmasone@chromium.org

[commit-bot: I haz the power, 2014-09-20 19:10:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/583263003/1

[commit-bot: I haz the power, 2014-09-20 19:14:40]

Committed patchset #1 (id:1) as f1a3d5ce93c49c7ff9f5eb76f54da34b232ddaaf

[commit-bot: I haz the power, 2014-09-20 19:15:17]

Patchset 1 (id:??) landed as
https://crrev.com/f324157fb51248250b91a87cd3d30a8928b79077
Cr-Commit-Position: refs/heads/master@{#295885}