Immediately open MTP and other eligible removable devices with media directory on mount.

ui/file_manager/file_manager/background/js/mock_volume_manager.js

Index: ui/file_manager/file_manager/background/js/mock_volume_manager.js
diff --git a/ui/file_manager/file_manager/background/js/mock_volume_manager.js b/ui/file_manager/file_manager/background/js/mock_volume_manager.js
index aa1003916a19fee66c391763c0b9f2022ebb12e6..b4c9dca4fa3adc2df0789138af1bbf2c355d30f2 100644
--- a/ui/file_manager/file_manager/background/js/mock_volume_manager.js
+++ b/ui/file_manager/file_manager/background/js/mock_volume_manager.js
@@ -7,7 +7,7 @@
  * @constructor
  */
 function MockVolumeManager() {
-  this.volumeInfoList = new cr.ui.ArrayDataModel([]);
+  this.volumeInfoList = new VolumeInfoList();
 
   this.createVolumeInfo(
       VolumeManagerCommon.VolumeType.DRIVE,
@@ -49,7 +49,7 @@ MockVolumeManager.prototype.createVolumeInfo =
     function(type, volumeId, label) {
   var volumeInfo =
       MockVolumeManager.createMockVolumeInfo(type, volumeId, label);
-  this.volumeInfoList.push(volumeInfo);
+  this.volumeInfoList.add(volumeInfo);
   return volumeInfo;
 };
 
@@ -60,11 +60,7 @@ MockVolumeManager.prototype.createVolumeInfo =
  * @return {VolumeInfo} Corresponding VolumeInfo.
  */
 MockVolumeManager.prototype.getVolumeInfo = function(entry) {
-  for (var i = 0; i < this.volumeInfoList.length; i++) {
-    if (this.volumeInfoList.item(i).volumeId === entry.volumeId)
-      return this.volumeInfoList.item(i);
-  }
-  return null;
+  return this.volumeInfoList.findByEntry(entry);
 };
 
 /**
@@ -125,3 +121,120 @@ MockVolumeManager.createMockVolumeInfo = function(type, volumeId, label) {
 
   return volumeInfo;
 };
+
+/**
+ * Mock class for VolumeManagerWrapper.
+ *
+ * TODO(mtomasz): Merge mocks once VolumeManagerWrapper and VolumeManager
+ * implement an identical interface.
+ * @constructor
+ */
+function MockVolumeManagerWrapper() {
+  this.volumeInfoList = new cr.ui.ArrayDataModel([]);
+  this.createVolumeInfo(
+      VolumeManagerCommon.VolumeType.DRIVE,
+      'drive',
+      str('DRIVE_DIRECTORY_LABEL'));
+  this.createVolumeInfo(
+      VolumeManagerCommon.VolumeType.DOWNLOADS,
+      'downloads',
+      str('DOWNLOADS_DIRECTORY_LABEL'));
+}
+/**
+ * @private {?VolumeManager}
+ */
+MockVolumeManagerWrapper.instance_ = null;
+/**
+ * Replaces the VolumeManager singleton with a MockVolumeManagerWrapper.
+ * @param {!MockVolumeManagerWrapper=} opt_singleton
+ */
+MockVolumeManagerWrapper.installMockSingleton = function(opt_singleton) {
+  MockVolumeManagerWrapper.instance_ =
+      opt_singleton || new MockVolumeManagerWrapper();
+  VolumeManager.getInstance = function() {
+    return Promise.resolve(MockVolumeManagerWrapper.instance_);
+  };
+};
+/**
+ * Creates, installs and returns a mock VolumeInfo instance.
+ *
+ * @param {!VolumeType} type
+ * @param {string} volumeId
+ * @param {string} label
+ *
+ * @return {!VolumeInfo}
+ */
+MockVolumeManagerWrapper.prototype.createVolumeInfo =
+    function(type, volumeId, label) {
+  var volumeInfo =
+      MockVolumeManagerWrapper.createMockVolumeInfo(type, volumeId, label);
+  this.volumeInfoList.push(volumeInfo);
+  return volumeInfo;
+};
+/**
+ * Returns the corresponding VolumeInfo.
+ *
+ * @param {MockFileEntry} entry MockFileEntry pointing anywhere on a volume.
+ * @return {VolumeInfo} Corresponding VolumeInfo.
+ */
+MockVolumeManagerWrapper.prototype.getVolumeInfo = function(entry) {
+  for (var i = 0; i < this.volumeInfoList.length; i++) {
+    if (this.volumeInfoList.item(i).volumeId === entry.volumeId)
+      return this.volumeInfoList.item(i);
+  }
+  return null;
+};
+/**
+ * Obtains location information from an entry.
+ * Current implementation can handle only fake entries.
+ *
+ * @param {Entry} entry A fake entry.
+ * @return {EntryLocation} Location information.
+ */
+MockVolumeManagerWrapper.prototype.getLocationInfo = function(entry) {
+  if (util.isFakeEntry(entry)) {
+    return new EntryLocation(this.volumeInfoList.item(0), entry.rootType, true,
+        true);
+  }
+  if (entry.filesystem.name === VolumeManagerCommon.VolumeType.DRIVE) {
+    var volumeInfo = this.volumeInfoList.item(0);
+    var isRootEntry = entry.fullPath === '/root';
+    return new EntryLocation(volumeInfo, VolumeManagerCommon.RootType.DRIVE,
+        isRootEntry, true);
+  }
+  throw new Error('Not implemented exception.');
+};
+/**
+ * @param {VolumeManagerCommon.VolumeType} volumeType Volume type.
+ * @return {VolumeInfo} Volume info.
+ */
+MockVolumeManagerWrapper.prototype.getCurrentProfileVolumeInfo =
+    function(volumeType) {
+  return VolumeManager.prototype.getCurrentProfileVolumeInfo.call(
+      this, volumeType);
+};
+/**
+ * Utility function to create a mock VolumeInfo.
+ * @param {VolumeType} type Volume type.
+ * @param {string} volumeId Volume id.
+ * @param {string} label Label.
+ * @return {VolumeInfo} Created mock VolumeInfo.
+ */
+MockVolumeManagerWrapper.createMockVolumeInfo =
+    function(type, volumeId, label) {
+  var fileSystem = new MockFileSystem(volumeId, 'filesystem:' + volumeId);
+  fileSystem.entries['/'] = new MockDirectoryEntry(fileSystem, '');
+  var volumeInfo = new VolumeInfo(
+      type,
+      volumeId,
+      fileSystem,
+      '',     // error
+      '',     // deviceType
+      '',     // devicePath
+      false,  // isReadonly
+      {isCurrentProfile: true, displayName: ''},  // profile
+      label,  // label
+      '',     // extensionId
+      false); // hasMedia
+  return volumeInfo;
+};