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

ios/web/webui/web_ui_ios_impl.h

Index: ios/web/webui/web_ui_ios_impl.h
diff --git a/ios/web/webui/web_ui_ios_impl.h b/ios/web/webui/web_ui_ios_impl.h
index 2d7a72ed84b885f3712f735f867fb5d4cb6ab56e..d7595e8161231802ea257a5ae2d1bdb325846e88 100644
--- a/ios/web/webui/web_ui_ios_impl.h
+++ b/ios/web/webui/web_ui_ios_impl.h
@@ -6,10 +6,10 @@
 #define IOS_WEB_WEBUI_WEB_UI_IOS_IMPL_H_
 
 #include <map>
+#include <memory>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "ios/public/provider/web/web_ui_ios.h"
@@ -70,7 +70,7 @@ class WebUIIOSImpl : public web::WebUIIOS,
   // Non-owning pointer to the WebStateImpl this WebUIIOS is associated with.
   WebStateImpl* web_state_;
 
-  scoped_ptr<WebUIIOSController> controller_;
+  std::unique_ptr<WebUIIOSController> controller_;
 
   DISALLOW_COPY_AND_ASSIGN(WebUIIOSImpl);
 };