Revert of Isolate nacl_loader_unittests

Revert of Isolate nacl_loader_unittests (https://codereview.chromium.org/322333006/)

Reason for revert:
This is causing the following error when running gyp_chromium with disable_nacl=1:

Traceback (most recent call last):
  File "./build/gyp_chromium", line 314, in <module>
    gyp_rc = gyp.main(args)
  File "/chromium/src/tools/gyp/pylib/gyp/__init__.py", line 527, in main
    return gyp_main(args)
  File "/chromium/src/tools/gyp/pylib/gyp/__init__.py", line 503, in gyp_main
    options.circular_check)
  File "/chromium/src/tools/gyp/pylib/gyp/__init__.py", line 129, in Load
    params['parallel'], params['root_targets'])
  File "/chromium/src/tools/gyp/pylib/gyp/input.py", line 2759, in Load
    RemoveLinkDependenciesFromNoneTargets(targets)
  File "/chromium/src/tools/gyp/pylib/gyp/input.py", line 1483, in RemoveLinkDependenciesFromNoneTargets
    if targets[t].get('variables', {}).get('link_dependency', 0):
KeyError: '/chromium/src/components/nacl.gyp:nacl_loader_unittests#target'


Original issue's description:
> Isolate nacl_loader_unittests
> 
> Isolate the Linux-only nacl_loader_unittests.
> 
> BUG=384515
> TBR=maruel
> NOTRY=true
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=278620

TBR=vadimsh@chromium.org,mseaborn@chromium.org,maruel@chromium.org,jln@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=384515
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=278643

[vsevik, 2014-06-20 07:43:19]

Created Revert of Isolate nacl_loader_unittests

[commit-bot: I haz the power, 2014-06-20 07:45:17]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/vsevik@chromium.org/348803004/1

[commit-bot: I haz the power, 2014-06-20 07:47:59]

Change committed as 278643