Let new pages use the custom user agent setting

The default is UA_OVERRIDE_INHERIT, which means that it will only
use the override value if there's a previous NavigationEntry.

Task-number: QTBUG-48891
Change-Id: Id5269b5ad2a4b0a78379c2b7df3c3e901cd2a485
Reviewed-by: Joerg Bornemann <[email protected]>

Author: Kai Koehne

src/core/web_contents_delegate_qt.cpp

@@ -99,6 +99,7 @@ content::WebContents *WebContentsDelegateQt::OpenURLFromTab(content::WebContents
     load_url_params.extra_headers = params.extra_headers;
     load_url_params.should_replace_current_entry = params.should_replace_current_entry;
     load_url_params.is_renderer_initiated = params.is_renderer_initiated;
+    load_url_params.override_user_agent = content::NavigationController::UA_OVERRIDE_TRUE;
 
     if (params.transferred_global_request_id != content::GlobalRequestID())
         load_url_params.transferred_global_request_id = params.transferred_global_request_id;