Fix the following issue in app notify login flow:

Fix the following issue in app notify login flow:
If the user is already logged in pre M17 and user sets
up notifications, the user will be asked to sign in.
AppNOtifyChannelUI::OnStateChanged is called more than
once before the oauth2 token is generated.

Fix it by:
Remembering if the wizard ever became visible instead of
whether the callback happened once.
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=112953

[asargent_no_longer_on_chrome, 2011-12-03 18:45:25]

LGTM

I assume you tested the case where the dialog is brought up, and then the user
just closes the sync setup tab?

http://codereview.chromium.org/8787013/diff/1/chrome/browser/extensions/app_n...
File chrome/browser/extensions/app_notify_channel_ui.cc (right):

http://codereview.chromium.org/8787013/diff/1/chrome/browser/extensions/app_n...
chrome/browser/extensions/app_notify_channel_ui.cc:134: wizard_shown_to_user_ =
wizard_visible;
nit: while this looks like it should work, would it be better to have this last
line be:

if (wizard_visible)
  wizard_shown_to_user_ = true;

?

That way any changes in the future wouldn't end up getting us confused and flip
wizard_shown_to_user_ from true back to false.