[CrOS Tether] Disconnect cleanly from active Tether networks when the user logs out or the Tether c…

[CrOS Tether] Disconnect cleanly from active Tether networks when the user logs out or the Tether component is killed.

Under normal circumstances, when a user disconnects from a Tether network, we start up an asynchronous connection flow. However, when these two edge cases occur, the Tether component is destroyed synchronously, and the full disconnection flow cannot complete (namely, the old Wi-Fi network supporting the Tether network is not removed). This CL fixes this problem by persisting the disconnecting Wi-Fi network GUID and removing it next time the Tether componentn starts up.

This CL also:
(1) Changes TetherDisconnector to an interface and moves the implementation to TetherDisconnectorImpl to make testing easier.
(2) Updates the shutdown flow for the Tether component by leaving the Tether TechnologyState intact during shutdown to prevent UI jank.

BUG=672263
Review-Url: https://codereview.chromium.org/2975483002
Cr-Commit-Position: refs/heads/master@{#486072}
Committed: https://chromium.googlesource.com/chromium/src/+/73dc567c7cfc4fc48722c29086deb3884e56a619

[Kyle Horimoto, 2017-07-06 21:34:27]

[email protected] changed reviewers:
+ [email protected]

[Ryan Hansberry, 2017-07-11 22:23:56]

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/initializer.h (left):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/initializer.h:136:
std::unique_ptr<TetherDisconnector> tether_disconnector_;
Was the change to this file necessary? (I don't feel that it was)

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/pref_names.cc (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/pref_names.cc:28:
"tether.disconnecting_wifi_network_id";
nit: _id -> _guid

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/tether_disconnector.cc (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/tether_disconnector.cc:15: void
TetherDisconnector::RegisterPrefs(PrefRegistrySimple* registry) {
You need to call this from Initializer.

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/tether_disconnector_impl.cc (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/tether_disconnector_impl.cc:61:
pref_service_->Set(prefs::kDisconnectingWifiNetworkGuid, base::Value(""));
nit: use ClearPref instead

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/tether_disconnector_impl.cc:226:
pref_service_->Set(prefs::kDisconnectingWifiNetworkGuid, base::Value(""));
same nit here, use ClearPref

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/tether_disconnector_impl.h (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/tether_disconnector_impl.h:44: static void
RegisterPrefs(PrefRegistrySimple* registry);
Why a RegisterPrefs on the interface and impl?

[Kyle Horimoto, 2017-07-12 01:42:59]

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/initializer.h (left):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/initializer.h:136:
std::unique_ptr<TetherDisconnector> tether_disconnector_;
On 2017/07/11 22:23:56, Ryan Hansberry wrote:
> Was the change to this file necessary? (I don't feel that it was)

Nope - changed.

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/pref_names.cc (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/pref_names.cc:28:
"tether.disconnecting_wifi_network_id";
On 2017/07/11 22:23:56, Ryan Hansberry wrote:
> nit: _id -> _guid

I'd like to keep this uniform with the rest of the file.

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/tether_disconnector.cc (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/tether_disconnector.cc:15: void
TetherDisconnector::RegisterPrefs(PrefRegistrySimple* registry) {
On 2017/07/11 22:23:56, Ryan Hansberry wrote:
> You need to call this from Initializer.

That's already done.

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/tether_disconnector_impl.cc (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/tether_disconnector_impl.cc:61:
pref_service_->Set(prefs::kDisconnectingWifiNetworkGuid, base::Value(""));
On 2017/07/11 22:23:56, Ryan Hansberry wrote:
> nit: use ClearPref instead

Done.

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/tether_disconnector_impl.h (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/tether_disconnector_impl.h:44: static void
RegisterPrefs(PrefRegistrySimple* registry);
On 2017/07/11 22:23:56, Ryan Hansberry wrote:
> Why a RegisterPrefs on the interface and impl?

Should only have been here - fixed.

[Ryan Hansberry, 2017-07-12 17:10:09]

The CQ bit was checked by [email protected]

[Ryan Hansberry, 2017-07-12 17:10:10]

lgtm

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/pref_names.cc (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/pref_names.cc:28:
"tether.disconnecting_wifi_network_id";
On 2017/07/12 01:42:59, Kyle Horimoto wrote:
> On 2017/07/11 22:23:56, Ryan Hansberry wrote:
> > nit: _id -> _guid
> 
> I'd like to keep this uniform with the rest of the file.

Oops, didn't notice that. Agreed.

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
File chromeos/components/tether/tether_disconnector.cc (right):

https://codereview.chromium.org/2975483002/diff/1/chromeos/components/tether/...
chromeos/components/tether/tether_disconnector.cc:15: void
TetherDisconnector::RegisterPrefs(PrefRegistrySimple* registry) {
On 2017/07/12 01:42:59, Kyle Horimoto wrote:
> On 2017/07/11 22:23:56, Ryan Hansberry wrote:
> > You need to call this from Initializer.
> 
> That's already done.

Oops, also did not see that on first glance.

[commit-bot: I haz the power, 2017-07-12 17:10:22]

CQ is trying da patch.

Follow status at:
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-07-12 20:19:31]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1499879409957160,
"parent_rev": "81dd1a25e0998f0fe85640856e476e56e5c4b059", "commit_rev":
"73dc567c7cfc4fc48722c29086deb3884e56a619"}

[commit-bot: I haz the power, 2017-07-12 20:19:44]

Description was changed from

==========
[CrOS Tether] Disconnect cleanly from active Tether networks when the user logs
out or the Tether component is killed.

Under normal circumstances, when a user disconnects from a Tether network, we
start up an asynchronous connection flow. However, when these two edge cases
occur, the Tether component is destroyed synchronously, and the full
disconnection flow cannot complete (namely, the old Wi-Fi network supporting the
Tether network is not removed). This CL fixes this problem by persisting the
disconnecting Wi-Fi network GUID and removing it next time the Tether componentn
starts up.

This CL also:
(1) Changes TetherDisconnector to an interface and moves the implementation to
TetherDisconnectorImpl to make testing easier.
(2) Updates the shutdown flow for the Tether component by leaving the Tether
TechnologyState intact during shutdown to prevent UI jank.

BUG=672263
==========

to

==========
[CrOS Tether] Disconnect cleanly from active Tether networks when the user logs
out or the Tether component is killed.

Under normal circumstances, when a user disconnects from a Tether network, we
start up an asynchronous connection flow. However, when these two edge cases
occur, the Tether component is destroyed synchronously, and the full
disconnection flow cannot complete (namely, the old Wi-Fi network supporting the
Tether network is not removed). This CL fixes this problem by persisting the
disconnecting Wi-Fi network GUID and removing it next time the Tether componentn
starts up.

This CL also:
(1) Changes TetherDisconnector to an interface and moves the implementation to
TetherDisconnectorImpl to make testing easier.
(2) Updates the shutdown flow for the Tether component by leaving the Tether
TechnologyState intact during shutdown to prevent UI jank.

BUG=672263

Review-Url: https://codereview.chromium.org/2975483002
Cr-Commit-Position: refs/heads/master@{#486072}
Committed:
https://chromium.googlesource.com/chromium/src/+/73dc567c7cfc4fc48722c29086de...
==========

[commit-bot: I haz the power, 2017-07-12 20:19:48]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/73dc567c7cfc4fc48722c29086de...