Remove "nacl_defines" from the GYP build.

Remove "nacl_defines" from the GYP build.

The following NaCl-related defines are now provided by
native_client/src/include/build_config.h instead of the build system:
  NACL_WINDOWS
  NACL_LINUX
  NACL_OSX
  NACL_ANDROID
  NACL_BUILD_ARCH
  NACL_BUILD_SUBARCH

This change removes these definitions from gyp(i) files, as they no longer need
to be provided by the build system.

BUG=440012
Committed: https://crrev.com/83538d2ebdbfab63c9d7a875405663ea91672259
Cr-Commit-Position: refs/heads/master@{#315429}

[teravest, 2015-02-09 20:29:10]

teravest@chromium.org changed reviewers:
+ mseaborn@chromium.org

[Mark Seaborn, 2015-02-09 20:42:09]

Nice.  LGTM.

Do the changes to mojo/ need to be copied into the Mojo repo?

[teravest, 2015-02-09 20:48:04]

On 2015/02/09 20:42:09, Mark Seaborn wrote:
> Nice.  LGTM.
> 
> Do the changes to mojo/ need to be copied into the Mojo repo?

Confusingly, the mojo/ files affected in this change are only in the Chromium
repo, so no changes need to be copied to the Mojo repo.

[teravest, 2015-02-09 21:24:31]

The CQ bit was checked by teravest@chromium.org

[commit-bot: I haz the power, 2015-02-09 21:25:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/912503003/1

[commit-bot: I haz the power, 2015-02-09 21:33:03]

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

[commit-bot: I haz the power, 2015-02-09 21:33:04]

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

[teravest, 2015-02-09 21:37:25]

teravest@chromium.org changed reviewers:
+ jamesr@chromium.org, thakis@chromium.org

[teravest, 2015-02-09 21:37:26]

+jamesr for mojo/
+thakis for chrome/chrome.gyp

[jamesr, 2015-02-09 21:38:46]

lgtm

[Nico, 2015-02-09 21:40:43]

lgtm

[teravest, 2015-02-09 21:41:20]

The CQ bit was checked by teravest@chromium.org

[commit-bot: I haz the power, 2015-02-09 21:42:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/912503003/1

[commit-bot: I haz the power, 2015-02-09 23:28:42]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-09 23:29:25]

Patchset 1 (id:??) landed as
https://crrev.com/83538d2ebdbfab63c9d7a875405663ea91672259
Cr-Commit-Position: refs/heads/master@{#315429}