Convert //content/browser from scoped_ptr to std::unique_ptr

content/browser/host_zoom_map_impl.cc

Index: content/browser/host_zoom_map_impl.cc
diff --git a/content/browser/host_zoom_map_impl.cc b/content/browser/host_zoom_map_impl.cc
index 298a66a8fc401fbfd5a3350b0ff125db9ec8d98d..cda61f938b931d1f515cfdb1ec174683579efed3 100644
--- a/content/browser/host_zoom_map_impl.cc
+++ b/content/browser/host_zoom_map_impl.cc
@@ -281,7 +281,7 @@ void HostZoomMapImpl::SetDefaultZoomLevel(double level) {
   default_zoom_level_ = level;
 }
 
-scoped_ptr<HostZoomMap::Subscription>
+std::unique_ptr<HostZoomMap::Subscription>
 HostZoomMapImpl::AddZoomLevelChangedCallback(
     const ZoomLevelChangedCallback& callback) {
   return zoom_level_changed_callbacks_.Add(callback);