[Extensions WebUI] Clean up ExtensionSettingsUIBrowserTest

[Extensions WebUI] Clean up ExtensionSettingsUIBrowserTest

Clean up ExtensionSettingsUIBrowserTest. Most notably, use the utility
class ChromeTestExtensionLoader() rather than re-implementing the load
extension functionality. Also remove some unneeded members, includes,
complexity, etc.

BUG=667587
Committed: https://crrev.com/55f2b623d3cb915156f24f7efdd09e3b64bd43e4
Cr-Commit-Position: refs/heads/master@{#436411}

[Devlin, 2016-11-28 23:01:51]

The CQ bit was checked by rdevlin.cronin@chromium.org to run a CQ dry run

[Devlin, 2016-11-28 23:02:58]

The CQ bit was checked by rdevlin.cronin@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-11-28 23:04:49]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Devlin, 2016-11-28 23:50:55]

rdevlin.cronin@chromium.org changed reviewers:
+ dbeam@chromium.org

[Devlin, 2016-11-28 23:50:56]

Dan, can you take a look when you get a chance?

[commit-bot: I haz the power, 2016-11-29 01:37:38]

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

[commit-bot: I haz the power, 2016-11-29 01:37:39]

Dry run: This issue passed the CQ dry run.

[Dan Beam, 2016-12-01 07:03:57]

i have very little idea what this code is doing

but i see a bunch of green boxes (good) and red lines (better!) so lgtm!

[Devlin, 2016-12-01 15:49:35]

The CQ bit was checked by rdevlin.cronin@chromium.org

[commit-bot: I haz the power, 2016-12-01 15:49:49]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-01 15:52:25]

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

[commit-bot: I haz the power, 2016-12-01 15:52:26]

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

[Devlin, 2016-12-01 22:10:16]

The CQ bit was checked by rdevlin.cronin@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-01 22:10:59]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-01 22:13:58]

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

[commit-bot: I haz the power, 2016-12-01 22:13:58]

Dry run: Try jobs failed on following builders:
  mac_chromium_compile_dbg_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)

[Devlin, 2016-12-05 20:35:25]

The CQ bit was checked by rdevlin.cronin@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-12-05 20:36:01]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-05 21:17:33]

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

[commit-bot: I haz the power, 2016-12-05 21:17:34]

Dry run: This issue passed the CQ dry run.

[Devlin, 2016-12-05 21:18:49]

The CQ bit was checked by rdevlin.cronin@chromium.org

[Devlin, 2016-12-05 21:18:49]

The patchset sent to the CQ was uploaded after l-g-t-m from dbeam@chromium.org
Link to the patchset: https://codereview.chromium.org/2536903002/#ps60001
(title: "rebase")

[commit-bot: I haz the power, 2016-12-05 21:19:35]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-12-05 21:25:59]

CQ is committing da patch.

Bot data: {"patchset_id": 60001, "attempt_start_ts": 1480972729482820,
"parent_rev": "ed1a9a1ccd95f7cade01b67b7c9a27716bfb731a", "commit_rev":
"f900b88598844d535464a50eb2d0ba5510e24964"}

[commit-bot: I haz the power, 2016-12-05 21:26:28]

Committed patchset #4 (id:60001)

[commit-bot: I haz the power, 2016-12-05 21:29:54]

Description was changed from

==========
[Extensions WebUI] Clean up ExtensionSettingsUIBrowserTest

Clean up ExtensionSettingsUIBrowserTest. Most notably, use the utility
class ChromeTestExtensionLoader() rather than re-implementing the load
extension functionality. Also remove some unneeded members, includes,
complexity, etc.

BUG=667587
==========

to

==========
[Extensions WebUI] Clean up ExtensionSettingsUIBrowserTest

Clean up ExtensionSettingsUIBrowserTest. Most notably, use the utility
class ChromeTestExtensionLoader() rather than re-implementing the load
extension functionality. Also remove some unneeded members, includes,
complexity, etc.

BUG=667587

Committed: https://crrev.com/55f2b623d3cb915156f24f7efdd09e3b64bd43e4
Cr-Commit-Position: refs/heads/master@{#436411}
==========

[commit-bot: I haz the power, 2016-12-05 21:29:55]

Patchset 4 (id:??) landed as
https://crrev.com/55f2b623d3cb915156f24f7efdd09e3b64bd43e4
Cr-Commit-Position: refs/heads/master@{#436411}