Phonehub: Set PhoneStatusProcessor as an observer to MultiDeviceSetupClient

- This change fixes a bug where we previously did not actually attach
  PhoneStatusProcessor as an observer to
  MultiDeviceSetupClient::Observer
- Fixes a bug where the phone name was not being displayed in the phone
  hub tray

Bug: 1106937
Fixed: 1141642
Test: chromeos_components_unittests
Change-Id: I4a7b04e34a5b7950b63a4b32dc633fece7c52e0a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2501063
Commit-Queue: Jimmy Gong <jimmyxgong@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821424}

chromeos/components/phonehub/phone_status_processor.cc

@@ -187,6 +187,7 @@ PhoneStatusProcessor::PhoneStatusProcessor(
 
   message_receiver_->AddObserver(this);
   feature_status_provider_->AddObserver(this);
+  multidevice_setup_client_->AddObserver(this);
 
   MaybeSetPhoneModelName(multidevice_setup_client_->GetHostStatus().second);
 }
@@ -194,6 +195,7 @@ PhoneStatusProcessor::PhoneStatusProcessor(
 PhoneStatusProcessor::~PhoneStatusProcessor() {
   message_receiver_->RemoveObserver(this);
   feature_status_provider_->RemoveObserver(this);
+  multidevice_setup_client_->RemoveObserver(this);
 }
 
 void PhoneStatusProcessor::SetReceivedNotifications(

chromeos/components/phonehub/phone_status_processor_unittest.cc

@@ -248,7 +248,7 @@ TEST_F(PhoneStatusProcessorTest, PhoneStatusUpdate) {
   EXPECT_FALSE(mutable_phone_model_->phone_status_model().has_value());
 }
 
-TEST_F(PhoneStatusProcessorTest, NoHostPhoneName) {
+TEST_F(PhoneStatusProcessorTest, PhoneName) {
   fake_multidevice_setup_client_->SetHostStatusWithDevice(
       std::make_pair(HostStatus::kHostVerified, base::nullopt));
   CreatePhoneStatusProcessor();
@@ -265,6 +265,17 @@ TEST_F(PhoneStatusProcessorTest, NoHostPhoneName) {
 
   EXPECT_EQ(0u, fake_notification_manager_->num_notifications());
   EXPECT_EQ(base::nullopt, mutable_phone_model_->phone_name());
+
+  // Create new fake phone with name.
+  const multidevice::RemoteDeviceRef kFakePhoneA =
+      multidevice::RemoteDeviceRefBuilder().SetName("Phone A").Build();
+
+  // Trigger a host status update and expect a new phone with new name to be
+  // updated.
+  fake_multidevice_setup_client_->SetHostStatusWithDevice(
+      std::make_pair(HostStatus::kHostVerified, kFakePhoneA));
+
+  EXPECT_EQ(base::UTF8ToUTF16("Phone A"), mutable_phone_model_->phone_name());
 }
 
 }  // namespace phonehub