[Devtools] Allow User-Agent header override for Websockets

content/browser/renderer_host/websocket_host.h

Index: content/browser/renderer_host/websocket_host.h
diff --git a/content/browser/renderer_host/websocket_host.h b/content/browser/renderer_host/websocket_host.h
index 626f6bea76e82ff6996b0d1d12efd2e1df5a87a7..45b08770c96a7cd9544815150bf12500915dc906 100644
--- a/content/browser/renderer_host/websocket_host.h
+++ b/content/browser/renderer_host/websocket_host.h
@@ -69,11 +69,13 @@ class CONTENT_EXPORT WebSocketHost {
   void OnAddChannelRequest(const GURL& socket_url,
                            const std::vector<std::string>& requested_protocols,
                            const url::Origin& origin,
+                           const std::string& additional_headers,
                            int render_frame_id);
 
   void AddChannel(const GURL& socket_url,
                   const std::vector<std::string>& requested_protocols,
                   const url::Origin& origin,
+                  const std::string& additional_headers,
                   int render_frame_id);
 
   void OnSendBlob(const std::string& uuid, uint64_t expected_size);