Revert of athena: Rename athena_resources target to athena_pak.

Revert of athena: Rename athena_resources target to athena_pak. (https://codereview.chromium.org/404683002/)

Reason for revert:
Breaks Google ChromeOS compile:

/bin/python src/build/gyp_chromium' in '/b/build/slave/google-chrome-rel-chromeos/build'
Updating projects from gyp files...
gyp: Dependency '/b/build/slave/google-chrome-rel-chromeos/build/src/athena/resources/athena_resources.gyp:athena_resources#target' not found while trying to load target /b/build/slave/google-chrome-rel-chromeos/build/src/athena/athena.gyp:athena_unittests#target

Original issue's description:
> athena: Rename athena_resources target to athena_pak.
> 
> That way we free a slot for when we add an athena_resources.grd.
> 
> BUG=None
> TEST=None
> R=oshima@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284268

TBR=oshima@chromium.org,tfarina@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=None

[waffles, 2014-07-19 01:21:14]

Created Revert of athena: Rename athena_resources target to athena_pak.

[waffles, 2014-07-19 01:22:22]

The CQ bit was unchecked by waffles@chromium.org

[tfarina, 2014-07-19 01:22:57]

Don't revert, I'm committing the fix.

[waffles, 2014-07-19 01:22:58]

On 2014/07/19 01:21:14, waffles wrote:
> Created Revert of athena: Rename athena_resources target to athena_pak.

tfarina has claimed responsibility for fixing, aborting revert