disable unused argument warning for clang builds.

disable unused argument warning for clang builds.

normally this warning is disabled but for nacl builds that
use clang its not.  this CL makes the option universally disabled
for all clang based builds.

BUG=libyuv:581
TESTED=native_client/build/gyp_nacl all.gyp -Dgtest_target_type=executable -Dmsan=0 & ninja -C out/Debug libyuv
R=kjellander@chromium.org

Committed: https://chromium.googlesource.com/libyuv/libyuv/+/2c77dbb976071c5185fca4ab475e72a2975b3993

[fbarchard1, 2016-04-06 23:54:06]

Description was changed from

==========
disable unused argument warning for clang builds.

normally this warning is disabled but for nacl builds that
use clang its not.  this CL makes the option universally disabled
for all clang based builds.

BUG=None
TESTED=native_client/build/gyp_nacl all.gyp -Dgtest_target_type=executable
-Dmsan=0 & ninja -C out/Debug libyuv
R=kjellander@chromium.org
==========

to

==========
disable unused argument warning for clang builds.

normally this warning is disabled but for nacl builds that
use clang its not.  this CL makes the option universally disabled
for all clang based builds.

BUG=libyuv:581
TESTED=native_client/build/gyp_nacl all.gyp -Dgtest_target_type=executable
-Dmsan=0 & ninja -C out/Debug libyuv
R=kjellander@chromium.org
==========

[kjellander_chromium, 2016-04-10 18:13:44]

lgtm

[fbarchard1, 2016-04-11 18:43:11]

Description was changed from

==========
disable unused argument warning for clang builds.

normally this warning is disabled but for nacl builds that
use clang its not.  this CL makes the option universally disabled
for all clang based builds.

BUG=libyuv:581
TESTED=native_client/build/gyp_nacl all.gyp -Dgtest_target_type=executable
-Dmsan=0 & ninja -C out/Debug libyuv
R=kjellander@chromium.org
==========

to

==========
disable unused argument warning for clang builds.

normally this warning is disabled but for nacl builds that
use clang its not.  this CL makes the option universally disabled
for all clang based builds.

BUG=libyuv:581
TESTED=native_client/build/gyp_nacl all.gyp -Dgtest_target_type=executable
-Dmsan=0 & ninja -C out/Debug libyuv
R=kjellander@chromium.org

Committed:
https://chromium.googlesource.com/libyuv/libyuv/+/2c77dbb976071c5185fca4ab475...
==========

[fbarchard1, 2016-04-11 18:43:12]

Committed patchset #2 (id:20001) manually as
2c77dbb976071c5185fca4ab475e72a2975b3993 (presubmit successful).