Cleanup usage of hard_dependency in grit targets.

Cleanup usage of hard_dependency in grit targets.

Since these targets are not static libraries, hard_dependency has no
effect (confirmed by Mark Mentovai and Tony Chang).

Files found with the following command line:

$ for f in $(g ls-files | grep strings.gyp ); do grep hard_dependency $f; echo $f; done
$ for f in $(g ls-files | grep resources.gyp ); do grep hard_dependency $f; echo $f; done

BUG=None
TEST=None
R=jochen@chromium.org,yoz@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284912

[jochen (gone - plz use gerrit), 2014-07-18 09:11:04]

lgtm

[tfarina, 2014-07-22 18:15:30]

+Benjamin for extensions/

[not at google - send to devlin, 2014-07-22 18:22:56]

lgtm

[tfarina, 2014-07-23 02:35:44]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2014-07-23 02:37:32]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/tfarina@chromium.org/393123004/40001

[commit-bot: I haz the power, 2014-07-23 07:06:38]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  win_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu_triggered...)

[commit-bot: I haz the power, 2014-07-23 07:55:46]

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

[commit-bot: I haz the power, 2014-07-23 07:55:47]

Try jobs failed on following builders:
  win_gpu_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/win_gpu_triggered...)

[tfarina, 2014-07-23 12:47:26]

The CQ bit was checked by tfarina@chromium.org

[commit-bot: I haz the power, 2014-07-23 12:48:54]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/tfarina@chromium.org/393123004/40001

[commit-bot: I haz the power, 2014-07-23 14:09:09]

Change committed as 284912