Files.app: Add FileSystemMetadataProvider.

ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider.js

Index: ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider.js
diff --git a/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider.js b/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider.js
new file mode 100644
index 0000000000000000000000000000000000000000..03531d54a9d197396667d10c76489dc945d62456
--- /dev/null
+++ b/ui/file_manager/file_manager/foreground/js/metadata/file_system_metadata_provider.js
@@ -0,0 +1,33 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/**
+ * @typedef {{modificationTime:Date, size:number}}
+ */
+var FileSystemMetadata;
+
+/**
+ * Metadata provider for FileEntry#getMetadata.
+ *
+ * @param {!MetadataProviderCache} cache
+ * @constructor
+ * @extends {NewMetadataProvider<!FileSystemMetadata>}
+ * @struct
+ */
+function FileSystemMetadataProvider(cache) {
+  NewMetadataProvider.call(this, cache, ['modificationTime', 'size']);
+}
+
+FileSystemMetadataProvider.prototype.__proto__ = NewMetadataProvider.prototype;
+
+/**
+ * @override
+ */
+FileSystemMetadataProvider.prototype.getImpl = function(requests) {
+  return Promise.all(requests.map(function(request) {
+    return new Promise(function(fulfill, reject) {
+      request.entry.getMetadata(fulfill, reject);
+    });
+  }));
+};