Hook up import history to media scanner.

ui/file_manager/file_manager/background/js/media_scanner_unittest.js

 // Copyright 2014 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.
 
 /**
- * Dummy private APIs.
+ * Stub out the metrics package.
+ * @type {!Object}
  */
-var chrome;
+var metrics = {
+  recordTime: function() {},
+  recordValue: function() {}
+};
 
-/**
- * Callbacks registered by setTimeout.
- * @type {Array.<function>}
- */
-var timeoutCallbacks;
+/** @type {!importer.DefaultMediaScanner} */
+var scanner;
 
-
-/**
- * @type {!importer.DefaultMediaScanner}
- */
-var scanner;
+/** @type {!importer.TestImportHistory} */
+var importHistory;
 
 // Set up the test components.
 function setUp() {
-  scanner = new importer.DefaultMediaScanner();
+
+  importHistory = new importer.TestImportHistory();
+  scanner = new importer.DefaultMediaScanner(
+      Promise.resolve(importHistory));
 }
 
 /**
  * Creates a subdirectory within a temporary file system for testing.
+ *
  * @param {string} directoryName Name of the test directory to create.  Must be
  *     unique within this test suite.
  */
 function makeTestFileSystemRoot(directoryName) {
   function makeTestFilesystem() {
     return new Promise(function(resolve, reject) {
       window.webkitRequestFileSystem(
           window.TEMPORARY,
-          1024*1024,
+          1024 * 1024,
           resolve,
           reject);
     });
   }
 
   return makeTestFilesystem()
       .then(
           // Create a directory, pretend that's the root.
           function(fs) {
             return new Promise(function(resolve, reject) {
@@ skipping 90 matching lines @@
                * Scans the directory.
                * @param {!DirectoryEntry} root
                */
               function(root) {
                 return scanner.scan([root]).whenFinished();
               })
           .then(assertResults.bind(null, expectedFiles)),
       callback);
 }
 
+/**
+ * Verifies that scanning a simple single-level directory structure works.
+ */
+function testIgnoresPreviouslyImports(callback) {
+  importHistory.importedPaths[
+      '/testIgnoresPreviouslyImports/oldimage1234.jpg'] =
+          [importer.Destination.GOOGLE_DRIVE];
+  var filenames = [
+    'oldimage1234.jpg',
+    'foo.jpg',
+    'bar.gif',
+    'baz.avi'
+  ];
+  var expectedFiles = [
+    '/testIgnoresPreviouslyImports/foo.jpg',
+    '/testIgnoresPreviouslyImports/bar.gif',
+    '/testIgnoresPreviouslyImports/baz.avi'
+  ];
+  reportPromise(
+      makeTestFileSystemRoot('testIgnoresPreviouslyImports')
+          .then(populateDir.bind(null, filenames))
+          .then(
+              /**
+               * Scans the directory.
+               * @param {!DirectoryEntry} root
+               */
+              function(root) {
+                return scanner.scan([root]).whenFinished();
+              })
+          .then(assertResults.bind(null, expectedFiles)),
+      callback);
+}
+
 function testMultiLevel(callback) {
   var filenames = [
     'foo.jpg',
     'bar',
     [
       'foo.0',
       'bar.0.jpg'
     ],
     [
       'foo.1',
@@ skipping 74 matching lines @@
 
 /**
  * Verifies the results of the media scan are as expected.
  * @param {!impoter.ScanResults} results
  */
 function assertResults(expected, results) {
   assertFileEntryPathsEqual(expected, results.getFileEntries());
   assertTrue(results.getScanDurationMs() > 0);
   // TODO(smckay): Add coverage for getTotalBytes.
 }