[SmartLock] Begin initial scan UI before attempting connection.

When scanning begins, a yellow icon with the tooltip "cannot connect..."
briefly pops up and is then replaced again by the spinner. This CL
prevents that visual jank by making sure |is_performing_initial_scan_|
is set to true before fetching lock screen state.

Bug: 890047, 921766
Change-Id: Ib41d4744f1eddcb510497b303a8a220716123f09
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1716156
Commit-Queue: Ryan Hansberry <hansberry@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#680547}

chromeos/components/proximity_auth/unlock_manager_impl.cc

@@ -164,8 +164,8 @@ void UnlockManagerImpl::SetRemoteDeviceLifeCycle(
     attempt_secure_connection_start_time_ =
         base::DefaultClock::GetInstance()->Now();
 
-    AttemptToStartRemoteDeviceLifecycle();
     SetIsPerformingInitialScan(true /* is_performing_initial_scan */);
+    AttemptToStartRemoteDeviceLifecycle();
   } else {
     ResetPerformanceMetricsTimestamps();
 

chromeos/components/proximity_auth/unlock_manager_impl_unittest.cc

@@ -557,9 +557,12 @@ TEST_F(ProximityAuthUnlockManagerImplTest,
        FindingConnection_UpdatesScreenlockState) {
   CreateUnlockManager(ProximityAuthSystem::SESSION_LOCK);
 
-  // TODO(crbug.com/890047): Remove this once the bug is resolved.
+  // Regression test for https://crbug.com/890047, ensuring that the NO_PHONE
+  // status doesn't incorrectly appear for a brief moment before the
+  // BLUETOOTH_CONNECTING spinner.
   EXPECT_CALL(proximity_auth_client_,
-              UpdateScreenlockState(ScreenlockState::NO_PHONE));
+              UpdateScreenlockState(ScreenlockState::NO_PHONE))
+      .Times(0);
 
   EXPECT_CALL(proximity_auth_client_,
               UpdateScreenlockState(ScreenlockState::BLUETOOTH_CONNECTING));
@@ -571,9 +574,12 @@ TEST_F(ProximityAuthUnlockManagerImplTest,
        Authenticating_UpdatesScreenlockState) {
   CreateUnlockManager(ProximityAuthSystem::SESSION_LOCK);
 
-  // TODO(crbug.com/890047): Remove this once the bug is resolved.
+  // Regression test for https://crbug.com/890047, ensuring that the NO_PHONE
+  // status doesn't incorrectly appear for a brief moment before the
+  // BLUETOOTH_CONNECTING spinner.
   EXPECT_CALL(proximity_auth_client_,
-              UpdateScreenlockState(ScreenlockState::NO_PHONE));
+              UpdateScreenlockState(ScreenlockState::NO_PHONE))
+      .Times(0);
 
   EXPECT_CALL(proximity_auth_client_,
               UpdateScreenlockState(ScreenlockState::BLUETOOTH_CONNECTING));