Add a warning for missing fileBrowserHandler permission.

Add a warning for missing fileBrowserHandler permission.

If file browser handlers are specified in the manifest, and the permission is
missing, then they will be ignored. This CL adds a warning so users are aware
of it.

TEST=unit_tests: *FileBrowserHandlerManifestTest.InvalidFileBrowserHandlers*
BUG=470494
Committed: https://crrev.com/dc219a796be153eeb36f34921f0f5bc107daf833
Cr-Commit-Position: refs/heads/master@{#322530}

[mtomasz, 2015-03-26 02:07:47]

mtomasz@chromium.org changed reviewers:
+ yoz@chromium.org

[mtomasz, 2015-03-26 02:07:58]

@yoz: PTAL. Thanks.

[Yoyo Zhou, 2015-03-26 18:31:51]

LGTM, thanks for following up.

[mtomasz, 2015-03-26 23:25:35]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2015-03-26 23:25:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1017163003/1

[commit-bot: I haz the power, 2015-03-27 00:49:40]

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

[commit-bot: I haz the power, 2015-03-27 00:49:41]

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_...)

[mtomasz, 2015-03-27 02:03:51]

The CQ bit was checked by mtomasz@chromium.org

[mtomasz, 2015-03-27 02:03:52]

The patchset sent to the CQ was uploaded after l-g-t-m from yoz@chromium.org
Link to the patchset: https://codereview.chromium.org/1017163003/#ps20001
(title: "Fixed tests.")

[commit-bot: I haz the power, 2015-03-27 02:04:02]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1017163003/20001

[commit-bot: I haz the power, 2015-03-27 02:27:30]

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

[commit-bot: I haz the power, 2015-03-27 02:27:31]

Try jobs failed on following builders:
  linux_chromium_gn_dbg on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[mtomasz, 2015-03-27 02:45:18]

The CQ bit was checked by mtomasz@chromium.org

[mtomasz, 2015-03-27 02:45:19]

The patchset sent to the CQ was uploaded after l-g-t-m from yoz@chromium.org
Link to the patchset: https://codereview.chromium.org/1017163003/#ps30008
(title: "Restored manifest.json.")

[commit-bot: I haz the power, 2015-03-27 02:45:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1017163003/30008

[commit-bot: I haz the power, 2015-03-27 03:04:05]

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

[commit-bot: I haz the power, 2015-03-27 03:04:06]

Try jobs failed on following builders:
  linux_chromium_compile_dbg_32_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

[mtomasz, 2015-03-27 03:17:04]

The CQ bit was checked by mtomasz@chromium.org

[mtomasz, 2015-03-27 03:17:04]

The patchset sent to the CQ was uploaded after l-g-t-m from yoz@chromium.org
Link to the patchset: https://codereview.chromium.org/1017163003/#ps50001
(title: "Comment out unused code.")

[commit-bot: I haz the power, 2015-03-27 03:17:13]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1017163003/50001

[commit-bot: I haz the power, 2015-03-27 04:38:11]

Committed patchset #4 (id:50001)

[commit-bot: I haz the power, 2015-03-27 04:38:51]

Patchset 4 (id:??) landed as
https://crrev.com/dc219a796be153eeb36f34921f0f5bc107daf833
Cr-Commit-Position: refs/heads/master@{#322530}