Because of bug 1145896. We should guard it with FirefoxAccounts.accountsExist. I think this is only an issue if you have account with synced devices and delete said account (as per the description in bug 1145896).

/r/5821 - Bug 1145897 - Check if accounts exist before returning client count in ActivityChooserModel. r=rnewman Pull down this commit: hg pull review -r 78e5febff180f95898a5eab7d2388a0ab9752c36

Comment on attachment 8580986 [details] MozReview Request: bz://1145897/mcomella https://reviewboard.mozilla.org/r/5819/#review4791 Ship It! ::: mobile/android/base/widget/ActivityChooserModel.java (Diff revision 1) > + !SyncAccounts.syncAccountsExist(mContext)) { I have a personal style preference for alignment here -- !s in a row. ::: mobile/android/base/widget/ActivityChooserModel.java (Diff revision 1) > + // account with clients was removed so we check if there are any active accounts. You can phrase this simply as: we can't possibly have any other clients if we don't have an FxA or old Sync account configured.

https://reviewboard.mozilla.org/r/5819/#review4839 > I have a personal style preference for alignment here -- !s in a row. I'd be fine with changing this but the two lines have the same indentation as the line inside the braces (i.e. `return false;`). > You can phrase this simply as: we can't possibly have any other clients if we don't have an FxA or old Sync account configured. Done.

Comment on attachment 8580986 [details] MozReview Request: bz://1145897/mcomella This should be uplifted with bug 1122302. Approval Request Comment [Feature/regressing bug #]: bug 1122302 [User impact if declined]: Users who remove sync accounts may still see a list of devices to send to because the DB is using stale data. [Describe test coverage new/current, TreeHerder]: None [Risks and why]: Low - we use an already tested method to see if accounts exist. In the worst case, we screwed up the logic and the "send to other devices" item will appear when it shouldn't or not appear when it should. [String/UUID change made/needed]: None