Convert //chrome/browser/ui from scoped_ptr to std::unique_ptr

chrome/browser/ui/views/dropdown_bar_host.cc

Index: chrome/browser/ui/views/dropdown_bar_host.cc
diff --git a/chrome/browser/ui/views/dropdown_bar_host.cc b/chrome/browser/ui/views/dropdown_bar_host.cc
index 6489874ef4f609fc74584c1f3bafb44239638d92..9c9d1a7f6348f22ae60869fcb77419d593cec671 100644
--- a/chrome/browser/ui/views/dropdown_bar_host.cc
+++ b/chrome/browser/ui/views/dropdown_bar_host.cc
@@ -43,7 +43,7 @@ void DropdownBarHost::Init(views::View* host_view,
 
   // The |clip_view| exists to paint to a layer so that it can clip descendent
   // Views which also paint to a Layer. See http://crbug.com/589497
-  scoped_ptr<views::View> clip_view(new views::View());
+  std::unique_ptr<views::View> clip_view(new views::View());
   clip_view->SetPaintToLayer(true);
   clip_view->layer()->SetFillsBoundsOpaquely(false);
   clip_view->layer()->SetMasksToBounds(true);