[CrOS PhoneHub] Correct TetherConnectionResult::kSuccess logging place.

Previously, this metric was logged in UpdateStatus(), which can be
influenced by connecting to a tether network in locations other than
via PhoneHub (e.g in OS Settings). This CL adds an attempt connection
tracking variable which is checked in UpdateStatus() before logging
the success metric.

Fixed: 1164570
Bug: 1106937
Change-Id: I9c070b7e644bcd6357bdb78f9b1e8a06bb275349
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2622953Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Regan Hsu <hsuregan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842825}

chromeos/components/phonehub/tether_controller_impl.cc

@@ -122,6 +122,7 @@ void TetherControllerImpl::AttemptConnection() {
   user_action_recorder_->RecordTetherConnectionAttempt();
   util::LogTetherConnectionResult(
       util::TetherConnectionResult::kAttemptConnection);
+  is_attempting_connection_ = true;
 
   FeatureState feature_state =
       multidevice_setup_client_->GetFeatureState(Feature::kInstantTethering);
@@ -393,11 +394,13 @@ void TetherControllerImpl::UpdateStatus() {
   PA_LOG(INFO) << "TetherController status update: " << status_ << " => "
                << status;
 
-  // Log the connection attempt result if it has succeed.
-  if (status == Status::kConnected)
+  status_ = status;
+
+  if (is_attempting_connection_ && status_ == Status::kConnected)
     util::LogTetherConnectionResult(util::TetherConnectionResult::kSuccess);
 
-  status_ = status;
+  if (status_ != Status::kConnecting)
+    is_attempting_connection_ = false;
 
   NotifyStatusChanged();
 }

chromeos/components/phonehub/tether_controller_impl.h

@@ -164,6 +164,9 @@ class TetherControllerImpl
       ConnectDisconnectStatus::kIdle;
   Status status_ = Status::kIneligibleForFeature;
 
+  // Whether this class is attempting a tether connection.
+  bool is_attempting_connection_ = false;
+
   network_config::mojom::NetworkStatePropertiesPtr tether_network_;
 
   std::unique_ptr<TetherNetworkConnector> connector_;