Update some uses of UTF conversions in chrome/browser to use the base:: namespace.

chrome/browser/ui/gtk/browser_actions_toolbar_gtk.cc

Index: chrome/browser/ui/gtk/browser_actions_toolbar_gtk.cc
diff --git a/chrome/browser/ui/gtk/browser_actions_toolbar_gtk.cc b/chrome/browser/ui/gtk/browser_actions_toolbar_gtk.cc
index 598fabc85a9a707683477986f47281d01e00efa9..2df92c07179a21e230b5a470f459bcbfbbd62007 100644
--- a/chrome/browser/ui/gtk/browser_actions_toolbar_gtk.cc
+++ b/chrome/browser/ui/gtk/browser_actions_toolbar_gtk.cc
@@ -1067,7 +1067,8 @@ gboolean BrowserActionsToolbarGtk::OnOverflowButtonPress(
     const Extension* extension = model_->toolbar_items()[model_index].get();
     BrowserActionButton* button = extension_button_map_[extension->id()].get();
 
-    overflow_menu_model_->AddItem(model_index, UTF8ToUTF16(extension->name()));
+    overflow_menu_model_->AddItem(model_index,
+                                  base::UTF8ToUTF16(extension->name()));
     overflow_menu_model_->SetIcon(overflow_menu_model_->GetItemCount() - 1,
                                   button->GetIcon());