Fixing debug GN build.

Fixing debug GN build.

Gate out ICU initialization for OS_NACL,
as it calls other code that is not built for nacl.
Undetected in gyp build since we always build the nacl irt as release
with gc-sections.

Stop building the ppb_var_deprecated_proxy as it's only used in the
trusted build for flash.
Undetected in gyp build since we always build the nacl irt as release
with gc-sections.

BUG=https://code.google.com/p/chromium/issues/detail?id=462791
TEST=trybots
R=dmichael@chromium.org,dpranke@chromium.org

Committed: https://crrev.com/961324d2110aaba0302b72ec88a78e7c36e4dfdd
Cr-Commit-Position: refs/heads/master@{#322070}

[dmichael (off chromium), 2015-03-24 17:51:27]

lgtm

[rvargas (doing something else), 2015-03-24 18:29:56]

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

[rvargas (doing something else), 2015-03-24 18:29:57]

lgtm

[bradn, 2015-03-24 18:30:05]

The CQ bit was checked by bradnelson@google.com

[commit-bot: I haz the power, 2015-03-24 18:30:41]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1034553002/1

[commit-bot: I haz the power, 2015-03-24 21:03:12]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-24 21:04:42]

Patchset 1 (id:??) landed as
https://crrev.com/961324d2110aaba0302b72ec88a78e7c36e4dfdd
Cr-Commit-Position: refs/heads/master@{#322070}