Convert //ios from scoped_ptr to std::unique_ptr.

ios/chrome/browser/ssl/ios_chrome_security_state_model_client.h

Index: ios/chrome/browser/ssl/ios_chrome_security_state_model_client.h
diff --git a/ios/chrome/browser/ssl/ios_chrome_security_state_model_client.h b/ios/chrome/browser/ssl/ios_chrome_security_state_model_client.h
index 63d032a0148f348a775eda01e7971d2b1b6e5012..4503c8daf7a578294a89fdf4cbd725f491e4c589 100644
--- a/ios/chrome/browser/ssl/ios_chrome_security_state_model_client.h
+++ b/ios/chrome/browser/ssl/ios_chrome_security_state_model_client.h
@@ -5,8 +5,9 @@
 #ifndef IOS_CHROME_BROWSER_SSL_IOS_CHROME_SECURITY_STATE_MODEL_CLIENT_H_
 #define IOS_CHROME_BROWSER_SSL_IOS_CHROME_SECURITY_STATE_MODEL_CLIENT_H_
 
+#include <memory>
+
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "components/security_state/security_state_model.h"
 #include "components/security_state/security_state_model_client.h"
 #include "ios/web/public/web_state/web_state_user_data.h"
@@ -38,7 +39,7 @@ class IOSChromeSecurityStateModelClient
   friend class web::WebStateUserData<IOSChromeSecurityStateModelClient>;
 
   web::WebState* web_state_;
-  scoped_ptr<security_state::SecurityStateModel> security_state_model_;
+  std::unique_ptr<security_state::SecurityStateModel> security_state_model_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSChromeSecurityStateModelClient);
 };