BackgroudModeManager now listens for APP_TERMINATING and shuts down background

BackgroudModeManager now listens for APP_TERMINATING and shuts down background
mode in all cases (now uses same code path for --keep-alive-for-test and for
background apps) - this is necessary because ExtensionsService does not
generate EXTENSION_UNLOADED notifications when the app shuts down as I thought.

With this fix, the extension API tests for background apps pass without
disabling background mode.


BUG=53021
TEST=extension API tests pass now with background mode enabled.

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=57266

[Andrew T Wilson (Slow), 2010-08-22 17:30:16]

Dmitry, this is a fix for that KeepAlive bug you encountered when writing up
your patch.

[Dmitry Titov, 2010-08-24 19:33:09]

LGTM with one note.

[Dmitry Titov, 2010-08-24 19:33:18]

http://codereview.chromium.org/3198007/diff/1/3
File chrome/browser/extensions/app_background_page_apitest.cc (left):

http://codereview.chromium.org/3198007/diff/1/3#oldcode17
chrome/browser/extensions/app_background_page_apitest.cc:17:
command_line->AppendSwitch(switches::kDisableBackgroundMode);
should we just remove kDisableBackgroundMode now that it is not used anymore?

[Andrew T Wilson (Slow), 2010-08-24 19:35:45]

On 2010/08/24 19:33:18, Dmitry Titov wrote:
> http://codereview.chromium.org/3198007/diff/1/3
> File chrome/browser/extensions/app_background_page_apitest.cc (left):
> 
> http://codereview.chromium.org/3198007/diff/1/3#oldcode17
> chrome/browser/extensions/app_background_page_apitest.cc:17:
> command_line->AppendSwitch(switches::kDisableBackgroundMode);
> should we just remove kDisableBackgroundMode now that it is not used anymore?

I want to leave kDisableBackgroundMode in to allow diagnosing bugs in background
mode (kind of like how we used to allow disabling workers). I'll take this out
post-M7.