Add private browsing logic

[sblatz]

Parent: #277

• Add the actual android component for private browsing so switching into the mode actually makes your session private
• Ensure private browsing is persistent if a user force closes the app but it was last left in private mode, we should start up in private mode

Mock-ups found here

┆Issue is synchronized with this Jira Task

[pocmo]

There's no component for "private browsing" directly. But when creating a Session you can specify whether it's private or not:
https://github.com/mozilla-mobile/android-components/blob/master/components/browser/session/src/main/java/mozilla/components/browser/session/Session.kt#L26

For situations where you need to pass a "UseCase" to a component you can alternate between AddNewTabUseCase and AddNewPrivateTabUseCase as you see fit.

That's how this looks like in your reference browser:
https://github.com/mozilla-mobile/reference-browser/blob/master/app/src/main/java/org/mozilla/reference/browser/tabs/TabsPanel.kt#L42-L48

If there's something missing or something that could be provided by a component then please let us know :)

[sblatz]

To confirm: this mode will not do any sort of tracking protection / cookie management, and will only stop users history from being stored once the session is complete?

@bbinto

[sblatz]

Note: private mode should trigger gboard private mode

[sblatz]

Do we have a specific link we want to use for "common myths about private browsing"?

@jonisavage

[sblatz]

@pocmo do we have the ability to set imeOptions on the AwesomeBar component from Fenix? I'd like to dynamically set flagNoPersonalizedLearning on the editText.

[pocmo]

@sblatz Not yet. I'll file something for that.

[sblatz]

@pocmo Great, thank you!

[bbinto]

To confirm: this mode will not do any sort of tracking protection / cookie management, and will only > stop users history from being stored once the session is complete?

@sblatz

We should not divert from the PB mode implementation in our other apps (feature parity): it should be PB with TP on by default.

[jonichan]

@sblatz here's a link you can use: https://support.mozilla.org/1/mobile/%VERSION%/%OS%/%LOCALE%/myths-private-browsing

Edit: Please ignore the link above. Michelle already posted the link in another issue. It will point to the same article.

[sblatz]

I believe tracking protection will land with this ticket: #97, and is not in the scope of this one.