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

ios/chrome/browser/favicon/ios_chrome_large_icon_cache_factory.h

Index: ios/chrome/browser/favicon/ios_chrome_large_icon_cache_factory.h
diff --git a/ios/chrome/browser/favicon/ios_chrome_large_icon_cache_factory.h b/ios/chrome/browser/favicon/ios_chrome_large_icon_cache_factory.h
index 6a20527c2af4a632fa4627beee623a196d961e24..e676da6b69c9094354707f31d9bece6972c7d579 100644
--- a/ios/chrome/browser/favicon/ios_chrome_large_icon_cache_factory.h
+++ b/ios/chrome/browser/favicon/ios_chrome_large_icon_cache_factory.h
@@ -5,8 +5,9 @@
 #ifndef IOS_CHROME_BROWSER_FAVICON_IOS_CHROME_LARGE_ICON_CACHE_FACTORY_H_
 #define IOS_CHROME_BROWSER_FAVICON_IOS_CHROME_LARGE_ICON_CACHE_FACTORY_H_
 
+#include <memory>
+
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "components/keyed_service/ios/browser_state_keyed_service_factory.h"
 
 class KeyedService;
@@ -37,7 +38,7 @@ class IOSChromeLargeIconCacheFactory : public BrowserStateKeyedServiceFactory {
   ~IOSChromeLargeIconCacheFactory() override;
 
   // BrowserStateKeyedServiceFactory implementation.
-  scoped_ptr<KeyedService> BuildServiceInstanceFor(
+  std::unique_ptr<KeyedService> BuildServiceInstanceFor(
       web::BrowserState* context) const override;
   web::BrowserState* GetBrowserStateToUse(
       web::BrowserState* context) const override;