Convert WindowOpenDisposition to an enum class.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 51f3bba4caad16978eb733a728677d84b7777844..cb76e7f6417ae5a583b55da45601160f68fe92bc 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -2056,7 +2056,7 @@ void WebContentsImpl::CreateNewWindow(
   create_params.opener_render_process_id = render_process_id;
   create_params.opener_render_frame_id = params.opener_render_frame_id;
   create_params.opener_suppressed = params.opener_suppressed;
-  if (params.disposition == NEW_BACKGROUND_TAB)
+  if (params.disposition == WindowOpenDisposition::NEW_BACKGROUND_TAB)
     create_params.initially_hidden = true;
   create_params.renderer_initiated_creation =
       main_frame_route_id != MSG_ROUTING_NONE;
@@ -2117,7 +2117,8 @@ void WebContentsImpl::CreateNewWindow(
           params.user_gesture, &was_blocked);
     }
     if (!was_blocked) {
-      OpenURLParams open_params(params.target_url, params.referrer, CURRENT_TAB,
+      OpenURLParams open_params(params.target_url, params.referrer,
+                                WindowOpenDisposition::CURRENT_TAB,
                                 ui::PAGE_TRANSITION_LINK,
                                 true /* is_renderer_initiated */);
       open_params.user_gesture = params.user_gesture;