mediaview: Hack to avoid Files app to freeze soon after login.

chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h

Index: chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h
diff --git a/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h b/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h
index d2afb37f48a950f686c82c3bd9fdde2a1e55e71a..ea13bb4087bc76d71a8f7dd93193446efbbb30ba 100644
--- a/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h
+++ b/chrome/browser/chromeos/arc/fileapi/arc_documents_provider_root.h
@@ -146,12 +146,10 @@ class ArcDocumentsProviderRoot : public ArcFileSystemOperationRunner::Observer {
 
   void AddWatcherWithDocumentId(const base::FilePath& path,
                                 const WatcherCallback& watcher_callback,
-                                const StatusCallback& callback,
                                 const std::string& document_id);
   void OnWatcherAdded(const base::FilePath& path,
-                      const StatusCallback& callback,
                       int64_t watcher_id);
-  void OnWatcherAddedButRemoved(const StatusCallback& callback, bool success);
+  void OnWatcherAddedButRemoved(bool success);
 
   void OnWatcherRemoved(const StatusCallback& callback, bool success);