Turn ArcSupportHost from Observer model to Delegate

chrome/browser/chromeos/arc/optin/arc_terms_of_service_default_negotiator.cc

Index: chrome/browser/chromeos/arc/optin/arc_terms_of_service_default_negotiator.cc
diff --git a/chrome/browser/chromeos/arc/optin/arc_terms_of_service_default_negotiator.cc b/chrome/browser/chromeos/arc/optin/arc_terms_of_service_default_negotiator.cc
index ca0fe339fb59128b7a44c4f9c2dadb84d2084f20..b0236fb91a794f5f3f2ffc4b17b5c2c9f7134046 100644
--- a/chrome/browser/chromeos/arc/optin/arc_terms_of_service_default_negotiator.cc
+++ b/chrome/browser/chromeos/arc/optin/arc_terms_of_service_default_negotiator.cc
@@ -20,7 +20,7 @@ ArcTermsOfServiceDefaultNegotiator::ArcTermsOfServiceDefaultNegotiator(
 }
 
 ArcTermsOfServiceDefaultNegotiator::~ArcTermsOfServiceDefaultNegotiator() {
-  support_host_->RemoveObserver(this);
+  support_host_->SetTermsOfServiceDelegate(nullptr);
 }
 
 void ArcTermsOfServiceDefaultNegotiator::StartNegotiationImpl() {
@@ -30,15 +30,15 @@ void ArcTermsOfServiceDefaultNegotiator::StartNegotiationImpl() {
   // This automatically updates all preferences.
   preference_handler_->Start();
 
-  support_host_->AddObserver(this);
+  support_host_->SetTermsOfServiceDelegate(this);
   support_host_->ShowTermsOfService();
 }
 
-void ArcTermsOfServiceDefaultNegotiator::OnWindowClosed() {
+void ArcTermsOfServiceDefaultNegotiator::OnTermsRejected() {
   // User cancels terms-of-service agreement UI by clicking "Cancel" button
   // or closing the window directly.
   DCHECK(preference_handler_);
-  support_host_->RemoveObserver(this);
+  support_host_->SetTermsOfServiceDelegate(nullptr);
   preference_handler_.reset();
 
   ReportResult(false);
@@ -49,7 +49,7 @@ void ArcTermsOfServiceDefaultNegotiator::OnTermsAgreed(
     bool is_backup_and_restore_enabled,
     bool is_location_service_enabled) {
   DCHECK(preference_handler_);
-  support_host_->RemoveObserver(this);
+  support_host_->SetTermsOfServiceDelegate(nullptr);
 
   // Update the preferences with the value passed from UI.
   preference_handler_->EnableMetrics(is_metrics_enabled);
@@ -60,19 +60,10 @@ void ArcTermsOfServiceDefaultNegotiator::OnTermsAgreed(
   ReportResult(true);
 }
 
-void ArcTermsOfServiceDefaultNegotiator::OnAuthSucceeded(
-    const std::string& auth_code) {
-  NOTREACHED();
-}
-
-void ArcTermsOfServiceDefaultNegotiator::OnRetryClicked() {
+void ArcTermsOfServiceDefaultNegotiator::OnTermsRetryClicked() {
   support_host_->ShowTermsOfService();
 }
 
-void ArcTermsOfServiceDefaultNegotiator::OnSendFeedbackClicked() {
-  NOTREACHED();
-}
-
 void ArcTermsOfServiceDefaultNegotiator::OnMetricsModeChanged(bool enabled,
                                                               bool managed) {
   support_host_->SetMetricsPreferenceCheckbox(enabled, managed);