Fix log spam on 10.6 due to NSWindowFullScreenButton.

Fix log spam on 10.6 due to NSWindowFullScreenButton.

NSWindowFullScreenButton is a 10.7 addition and calling
-standardWindowButton: with it on 10.6 results in log
spam of the form:

"unrecognized button type 7"

BUG=none

Committed: https://crrev.com/34f8293d798313b84fd29ca804a8c50a797dc55f
Cr-Commit-Position: refs/heads/master@{#315089}

[Alexei Svitkine (slow), 2015-02-06 16:21:44]

asvitkine@chromium.org changed reviewers:
+ erikchen@chromium.org

[erikchen, 2015-02-06 18:28:45]

lgtm

[Alexei Svitkine (slow), 2015-02-06 18:32:39]

The CQ bit was checked by asvitkine@chromium.org

[commit-bot: I haz the power, 2015-02-06 18:33:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/905803002/1

[commit-bot: I haz the power, 2015-02-06 19:01:44]

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

[commit-bot: I haz the power, 2015-02-06 19:01:45]

Try jobs failed on following builders:
  mac_chromium_rel_ng on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Alexei Svitkine (slow), 2015-02-06 19:20:54]

New patchsets have been uploaded after l-g-t-m from erikchen@chromium.org

[Alexei Svitkine (slow), 2015-02-06 19:21:13]

The CQ bit was checked by asvitkine@chromium.org

[commit-bot: I haz the power, 2015-02-06 19:21:56]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/905803002/20001

[commit-bot: I haz the power, 2015-02-06 19:53:32]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-06 19:54:24]

Patchset 2 (id:??) landed as
https://crrev.com/34f8293d798313b84fd29ca804a8c50a797dc55f
Cr-Commit-Position: refs/heads/master@{#315089}