[CrOS Instant Tethering] Handle LAST_PROVISIONING_FAILED enum

A new change on the Android side now causes the phone to respond with
LAST_PROVISIONING_FAILED if the last attempt to run provisioning failed.
This CL addresses the case for when the device was offline last time it
checked, or there was some sort of network error when checking.

Bug: 872473
Change-Id: Ia28f9077990a5a991b3968a6da100222940c11be
Reviewed-on: https://chromium-review.googlesource.com/c/1357656
Commit-Queue: Regan Hsu <hsuregan@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#612909}

chromeos/components/tether/host_scanner_operation.cc

@@ -50,7 +50,10 @@ bool IsTetheringAvailableWithValidDeviceStatus(
               TetherAvailabilityResponse_ResponseCode_SETUP_NEEDED ||
       response_code ==
           TetherAvailabilityResponse_ResponseCode::
-              TetherAvailabilityResponse_ResponseCode_TETHER_AVAILABLE) {
+              TetherAvailabilityResponse_ResponseCode_TETHER_AVAILABLE ||
+      response_code ==
+          TetherAvailabilityResponse_ResponseCode::
+              TetherAvailabilityResponse_ResponseCode_LAST_PROVISIONING_FAILED) {
     return true;
   }
 

chromeos/components/tether/host_scanner_operation_unittest.cc

@@ -384,6 +384,9 @@ TEST_F(
 }
 
 TEST_F(HostScannerOperationTest, DISABLED_TestMultipleDevices) {
+  // TODO(khorimoto): Test the case for when the response is
+  // TetherAvailabilityResponse_ResponseCode_LAST_PROVISIONING_FAILED, which
+  // is currently equivalent to a SuccessfulTetherAvailabilityResponse.
   EXPECT_CALL(*mock_tether_host_response_recorder_,
               RecordSuccessfulTetherAvailabilityResponse(test_devices_[0]));
   EXPECT_CALL(*mock_tether_host_response_recorder_,

chromeos/components/tether/proto/tether.proto

@@ -73,6 +73,7 @@ message TetherAvailabilityResponse {
     NO_SIM_CARD = 4;
     NOTIFICATIONS_DISABLED_LEGACY = 5;
     NOTIFICATIONS_DISABLED_WITH_NOTIFICATION_CHANNEL = 6;
+    LAST_PROVISIONING_FAILED = 7;
   }
 
   optional ResponseCode response_code = 1;