Turn ArcSupportHost from Observer model to Delegate

chrome/browser/chromeos/arc/auth/arc_manual_auth_code_fetcher.h

Index: chrome/browser/chromeos/arc/auth/arc_manual_auth_code_fetcher.h
diff --git a/chrome/browser/chromeos/arc/auth/arc_manual_auth_code_fetcher.h b/chrome/browser/chromeos/arc/auth/arc_manual_auth_code_fetcher.h
index 238275992f345327942a54676e617ef16188f896..9ecd3f0e1a64fbe097b58b8d3a37f2d2590e8604 100644
--- a/chrome/browser/chromeos/arc/auth/arc_manual_auth_code_fetcher.h
+++ b/chrome/browser/chromeos/arc/auth/arc_manual_auth_code_fetcher.h
@@ -23,7 +23,7 @@ class ArcAuthContext;
 // Implements the auth token fetching procedure with user's "SIGN IN" button
 // click.
 class ArcManualAuthCodeFetcher : public ArcAuthInfoFetcher,
-                                 public ArcSupportHost::Observer {
+                                 public ArcSupportHost::AuthHandler {
  public:
   ArcManualAuthCodeFetcher(ArcAuthContext* context,
                            ArcSupportHost* support_host);
@@ -38,10 +38,10 @@ class ArcManualAuthCodeFetcher : public ArcAuthInfoFetcher,
   // Called when HTTP request gets ready.
   void OnContextPrepared(net::URLRequestContextGetter* request_context_getter);
 
-  // ArcSupportHost::Observer:
+  // ArcSupportHost::AuthHandler:
   void OnAuthSucceeded(const std::string& auth_code) override;
   void OnAuthFailed() override;
-  void OnRetryClicked() override;
+  void OnAuthRetry() override;
 
   ArcAuthContext* const context_;
   ArcSupportHost* const support_host_;