Update SupportsUserData uses with unique_ptr.

chrome/browser/ssl/ssl_error_handler.h

Index: chrome/browser/ssl/ssl_error_handler.h
diff --git a/chrome/browser/ssl/ssl_error_handler.h b/chrome/browser/ssl/ssl_error_handler.h
index 319eb612184784a1e91c865a775d112b432bb441..c1ae36c9987e252ddbf944b4b293c8702386e863 100644
--- a/chrome/browser/ssl/ssl_error_handler.h
+++ b/chrome/browser/ssl/ssl_error_handler.h
@@ -62,6 +62,8 @@ class SSLErrorHandler : public content::WebContentsUserData<SSLErrorHandler>,
  public:
   typedef base::Callback<void(content::WebContents*)> TimerStartedCallback;
 
+  ~SSLErrorHandler() override;
+
   // Events for UMA. Do not rename or remove values, add new values to the end.
   // Public for testing.
   enum UMAEvent {
@@ -143,8 +145,6 @@ class SSLErrorHandler : public content::WebContentsUserData<SSLErrorHandler>,
       const base::Callback<void(content::CertificateRequestResultType)>&
           callback);
 
-  ~SSLErrorHandler() override;
-
   // Called when an SSL cert error is encountered. Triggers a captive portal
   // check and fires a one shot timer to wait for a "captive portal detected"
   // result to arrive. Protected for testing.