Stop foreground depending on background in gyp v2

ui/file_manager/externs/background/media_scanner.js

Index: ui/file_manager/externs/background/media_scanner.js
diff --git a/ui/file_manager/externs/background/media_scanner.js b/ui/file_manager/externs/background/media_scanner.js
new file mode 100644
index 0000000000000000000000000000000000000000..0b4fe9b250b003e18d2032f813dae3b1d372b646
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+++ b/ui/file_manager/externs/background/media_scanner.js
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+// Copyright 2017 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 importer;
+
+/**
+ * Class representing the results of a scan operation.
+ *
+ * @interface
+ */
+importer.MediaScanner = function() {};
+
+/**
+ * @typedef {function(!importer.ScanEvent, importer.ScanResult)}
+ */
+importer.ScanObserver;
+
+/**
+ * Initiates scanning.
+ *
+ * @param {!DirectoryEntry} directory
+ * @param {!importer.ScanMode} mode
+ * @return {!importer.ScanResult} ScanResult object representing the scan
+ *     job both while in-progress and when completed.
+ */
+importer.MediaScanner.prototype.scanDirectory;
+
+/**
+ * Initiates scanning.
+ *
+ * @param {!Array<!FileEntry>} entries Must be non-empty, and all entires
+ *     must be of a supported media type. Individually supplied files
+ *     are not subject to deduplication.
+ * @param {!importer.ScanMode} mode The method to detect new files.
+ * @return {!importer.ScanResult} ScanResult object representing the scan
+ *     job for the explicitly supplied entries.
+ */
+importer.MediaScanner.prototype.scanFiles;
+
+/**
+ * Adds an observer, which will be notified on scan events.
+ *
+ * @param {!importer.ScanObserver} observer
+ */
+importer.MediaScanner.prototype.addObserver;
+
+/**
+ * Remove a previously registered observer.
+ *
+ * @param {!importer.ScanObserver} observer
+ */
+importer.MediaScanner.prototype.removeObserver;
+
+/**
+ * Class representing the results of a scan operation.
+ *
+ * @interface
+ */
+importer.ScanResult = function() {};
+
+/**
+ * @return {boolean} true if scanning is complete.
+ */
+importer.ScanResult.prototype.isFinal;
+
+/**
+ * Notifies the scan to stop working. Some in progress work
+ * may continue, but no new work will be undertaken.
+ */
+importer.ScanResult.prototype.cancel;
+
+/**
+ * @return {boolean} True if the scan has been canceled. Some
+ * work started prior to cancelation may still be ongoing.
+ */
+importer.ScanResult.prototype.canceled;
+
+/**
+ * @param {number} count Sets the total number of candidate entries
+ *     that were checked while scanning. Used when determining
+ *     total progress.
+ */
+importer.ScanResult.prototype.setCandidateCount;
+
+/**
+ * Event method called when a candidate has been processed.
+ * @param {number} count
+ */
+importer.ScanResult.prototype.onCandidatesProcessed;
+
+/**
+ * Returns all files entries discovered so far. The list will be
+ * complete only after scanning has completed and {@code isFinal}
+ * returns {@code true}.
+ *
+ * @return {!Array<!FileEntry>}
+ */
+importer.ScanResult.prototype.getFileEntries;
+
+/**
+ * Returns all files entry duplicates discovered so far.
+ * The list will be
+ * complete only after scanning has completed and {@code isFinal}
+ * returns {@code true}.
+ *
+ * Duplicates are files that were found during scanning,
+ * where not found in import history, and were matched to
+ * an existing entry either in the import destination, or
+ * to another entry within the scan itself.
+ *
+ * @return {!Array<!FileEntry>}
+ */
+importer.ScanResult.prototype.getDuplicateFileEntries;
+
+/**
+ * Returns a promise that fires when scanning is finished
+ * normally or has been canceled.
+ *
+ * @return {!Promise<!importer.ScanResult>}
+ */
+importer.ScanResult.prototype.whenFinal;
+
+/**
+ * @return {!importer.ScanResult.Statistics}
+ */
+importer.ScanResult.prototype.getStatistics;
+
+/**
+ * @typedef {{
+ *   scanDuration: number,
+ *   newFileCount: number,
+ *   duplicates: !Object<!importer.Disposition, number>,
+ *   sizeBytes: number,
+ *   candidates: {
+ *     total: number,
+ *     processed: number
+ *   },
+ *   progress: number
+ * }}
+ */
+importer.ScanResult.Statistics;