Media Galleries: Add MediaGalleriesPreferences::GalleryChangeObserver class.

Media Galleries: Add MediaGalleriesPreferences::GalleryChangeObserver class.

This lets interested parties such as media gallery permission dialogs get
notifications for preferences changes.

BUG=158849
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=179871

[vandebo (ex-Chrome), 2013-01-31 01:27:55]

LGTM w/ nit

https://codereview.chromium.org/12114019/diff/1/chrome/browser/media_gallery/...
File chrome/browser/media_gallery/media_galleries_preferences.cc (right):

https://codereview.chromium.org/12114019/diff/1/chrome/browser/media_gallery/...
chrome/browser/media_gallery/media_galleries_preferences.cc:183: if (!list) {
To remove the code duplication, what do you think about putting the for loop in
an if (list) block and removing the early exit?

[Lei Zhang, 2013-01-31 01:34:34]

https://codereview.chromium.org/12114019/diff/1/chrome/browser/media_gallery/...
File chrome/browser/media_gallery/media_galleries_preferences.cc (right):

https://codereview.chromium.org/12114019/diff/1/chrome/browser/media_gallery/...
chrome/browser/media_gallery/media_galleries_preferences.cc:183: if (!list) {
On 2013/01/31 01:27:56, vandebo wrote:
> To remove the code duplication, what do you think about putting the for loop
in
> an if (list) block and removing the early exit?

Done.

[vandebo (ex-Chrome), 2013-01-31 01:35:46]

LG

[vandebo (ex-Chrome), 2013-01-31 01:35:55]

LGTM

[commit-bot: I haz the power, 2013-01-31 01:40:04]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/thestig@chromium.org/12114019/7001

[commit-bot: I haz the power, 2013-01-31 04:17:16]

Retried try job too often on win_rel for step(s) base_unittests, browser_tests,
cacheinvalidation_unittests, check_deps, chrome_frame_net_tests,
chrome_frame_unittests, chromedriver2_unittests, components_unittests,
content_browsertests, content_unittests, crypto_unittests, gpu_unittests,
installer_util_unittests, interactive_ui_tests, ipc_tests, jingle_unittests,
media_unittests, mini_installer_test, nacl_integration, net_unittests,
ppapi_unittests, printing_unittests, remoting_unittests, sql_unittests,
sync_integration_tests, sync_unit_tests, unit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_rel&nu...

[commit-bot: I haz the power, 2013-01-31 07:11:34]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/thestig@chromium.org/12114019/7001

[commit-bot: I haz the power, 2013-01-31 11:58:11]

Change committed as 179871