Reland of r266437: [Files.app] Use getDriveEntryProperties() to retrieve metadata

chrome/common/extensions/api/file_browser_private.idl

Index: chrome/common/extensions/api/file_browser_private.idl
diff --git a/chrome/common/extensions/api/file_browser_private.idl b/chrome/common/extensions/api/file_browser_private.idl
index 326f84b31c8731a78bbd3fb6d9000806e397d505..dc3bca43a9aaa13d11e513806753604d30585c46 100644
--- a/chrome/common/extensions/api/file_browser_private.idl
+++ b/chrome/common/extensions/api/file_browser_private.idl
@@ -162,6 +162,12 @@ dictionary FileTask {
 
 // Drive file properties.
 dictionary DriveEntryProperties {
+  // Size of this file.
+  double? fileSize;
+
+  // Timestamp of entry update time, in milliseconds past the epoch.
+  double? lastModifiedTime;
+
   // URL to the Drive thumbnail image for this file.
   DOMString? thumbnailUrl;