Plumb file system permission into WebviewGuest.

chrome/browser/guest_view/web_view/web_view_guest.h

Index: chrome/browser/guest_view/web_view/web_view_guest.h
diff --git a/chrome/browser/guest_view/web_view/web_view_guest.h b/chrome/browser/guest_view/web_view/web_view_guest.h
index f7b6d2ba0a7ee606a241e1cb30202a32031a3d32..8a4cd07401903294457130dc58c05bcb02f8a577 100644
--- a/chrome/browser/guest_view/web_view/web_view_guest.h
+++ b/chrome/browser/guest_view/web_view/web_view_guest.h
@@ -182,6 +182,14 @@ class WebViewGuest : public GuestView<WebViewGuest>,
 
   void CancelGeolocationPermissionRequest(int bridge_id);
 
+  void RequestFileSystemPermission(const GURL& url,
+                                   const base::Callback<void(bool)>& callback);
+
+  void OnWebViewFileSystemPermissionResponse(
+      const base::Callback<void(bool)>& callback,
+      bool allow,
+      const std::string& user_input);
+
   void OnWebViewMediaPermissionResponse(
       const content::MediaStreamRequest& request,
       const content::MediaResponseCallback& callback,