Show number of remaining files when copying directories.

ui/file_manager/file_manager/background/js/file_operation_util.js

 // Copyright 2013 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.
 
 /**
  * Utilities for file operations.
  */
 var fileOperationUtil = {};
 
 /**
@@ skipping 594 matching lines @@
  * @param {function()} successCallback Callback run on success.
  * @param {function(fileOperationUtil.Error)} errorCallback Callback run on
  *     error.
  */
 fileOperationUtil.Task.prototype.run = function(
     entryChangedCallback, progressCallback, successCallback, errorCallback) {
 };
 
 /**
  * Get states of the task.
- * TOOD(hirono): Removes this method and sets a task to progress events.
+ * TODO(hirono): Removes this method and sets a task to progress events.
  * @return {Object} Status object.
  */
 fileOperationUtil.Task.prototype.getStatus = function() {
   var processingEntry = this.sourceEntries[this.processingSourceIndex_];
+  var numRemainingItems = 0;
+
+  var resolvedEntryMap;
+  if (this.processingEntries && this.processingEntries.length > 0)
+    resolvedEntryMap = this.processingEntries[this.processingSourceIndex_];
+
+  if (resolvedEntryMap) {
+    for (var key in resolvedEntryMap) {

[fukino, 2017/06/26 05:15:15]

not lgtm, since this changes asymptotic time complexity of updating the
progress, and the overhead might slow down the copy operation.

[tetsui, 2017/06/26 06:51:20]

Done.

+      if (resolvedEntryMap.hasOwnProperty(key) &&
+          resolvedEntryMap[key].processedBytes === 0) {
+        numRemainingItems++;
+      }
+    }
+    for (var i = this.processingSourceIndex_ + 1;
+         i < this.processingEntries.length; i++) {
+      numRemainingItems += Object.keys(this.processingEntries[i] || {}).length;
+    }
+  } else {
+    numRemainingItems = this.sourceEntries.length - this.processingSourceIndex_;
+  }
   return {
     operationType: this.operationType,
-    numRemainingItems: this.sourceEntries.length - this.processingSourceIndex_,
+    numRemainingItems: numRemainingItems,
     totalBytes: this.totalBytes,
     processedBytes: this.processedBytes,
     processingEntryName: processingEntry ? processingEntry.name : ''
   };
 };
 
 /**
  * Obtains the number of total processed bytes.
  * @return {number} Number of total processed bytes.
  * @private
@@ skipping 659 matching lines @@
 fileOperationUtil.EventRouter.prototype.sendDeleteEvent = function(
     reason, task) {
   var event = /** @type {FileOperationProgressEvent} */ (new Event('delete'));
   event.reason = reason;
   event.taskId = task.taskId;
   event.entries = task.entries;
   event.totalBytes = task.totalBytes;
   event.processedBytes = task.processedBytes;
   this.dispatchEvent(event);
 };