Add background-wide file metadata cache.

ui/file_manager/file_manager/background/js/file_operation_util.js

Index: ui/file_manager/file_manager/background/js/file_operation_util.js
diff --git a/ui/file_manager/file_manager/background/js/file_operation_util.js b/ui/file_manager/file_manager/background/js/file_operation_util.js
index 1a7b337b7b02412de569d22aae0b9138b4db8859..621caa00cb229c36a7f09b5232dccf6ca6be4250 100644
--- a/ui/file_manager/file_manager/background/js/file_operation_util.js
+++ b/ui/file_manager/file_manager/background/js/file_operation_util.js
@@ -152,7 +152,7 @@ fileOperationUtil.resolveRecursively_ = function(
           onError);
     } else {
       // For a file, annotate the file size.
-      entry.getMetadata(function(metadata) {
+      getEntryMetadata(entry).then(function(metadata) {
         entry.size = metadata.size;
         --numRunningTasks;
         maybeInvokeCallback();