Files.app: Add ContentMetadataProvider class.

ui/file_manager/file_manager/foreground/js/metadata/content_metadata_provider_unittest.js

Index: ui/file_manager/file_manager/foreground/js/metadata/content_metadata_provider_unittest.js
diff --git a/ui/file_manager/file_manager/foreground/js/metadata/content_metadata_provider_unittest.js b/ui/file_manager/file_manager/foreground/js/metadata/content_metadata_provider_unittest.js
new file mode 100644
index 0000000000000000000000000000000000000000..06c9b3f0528d2975c6a7036b96161999e659a8a3
--- /dev/null
+++ b/ui/file_manager/file_manager/foreground/js/metadata/content_metadata_provider_unittest.js
@@ -0,0 +1,48 @@
+// 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.
+
+var entryA = {
+  toURL: function() { return "filesystem://A"; }
+};
+
+var entryB = {
+  toURL: function() { return "filesystem://B"; }
+};
+
+function testExternalMetadataProviderBasic(callback) {
+  // Mocking SharedWorker's port.
+  var port = {
+    postMessage: function(message) {
+      if (message.verb === 'request') {
+        this.onmessage({
+          data: {
+            verb: 'result',
+            arguments: [
+              message.arguments[0],
+              {
+                thumbnailURL: message.arguments[0] + ',url',
+                thumbnailTransform: message.arguments[0] + ',transform'
+              }
+            ]
+          }
+        });
+      }
+    },
+    start: function() {}
+  };
+  var cache = new MetadataProviderCache();
+  var provider = new ContentMetadataProvider(cache, port);
+  reportPromise(provider.get(
+      [entryA, entryB],
+      ['thumbnailURL', 'thumbnailTransform']).then(
+          function(results) {
+            assertEquals(2, results.length);
+            assertEquals('filesystem://A,url', results[0].thumbnailURL);
+            assertEquals(
+                'filesystem://A,transform', results[0].thumbnailTransform);
+            assertEquals('filesystem://B,url', results[1].thumbnailURL);
+            assertEquals(
+                'filesystem://B,transform', results[1].thumbnailTransform);
+          }), callback);
+}