Fix a bug that unmounting devices on the policy update can be a busy loop.

chrome/browser/chromeos/file_manager/volume_manager.cc

 // 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.
 
 #include "chrome/browser/chromeos/file_manager/volume_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include "base/bind.h"
@@ skipping 664 matching lines @@
   // TODO(mtomasz): Introduce own type, and avoid using MountError internally,
   // since it is related to cros disks only.
   const chromeos::MountError mount_error = error == base::File::FILE_OK
                                                ? chromeos::MOUNT_ERROR_NONE
                                                : chromeos::MOUNT_ERROR_UNKNOWN;
   linked_ptr<Volume> volume(Volume::CreateForProvidedFileSystem(
       file_system_info, MOUNT_CONTEXT_UNKNOWN));
   DoUnmountEvent(mount_error, volume);
 }
 
+void VolumeManager::OnExternalStorageDisabledChangedUnmountCallback(
+    chromeos::MountError error_code) {
+  if (disk_mount_manager_->mount_points().empty())
+    return;
+  // Repeat until unmount all paths
+  const std::string& mount_path =
+      disk_mount_manager_->mount_points().begin()->second.mount_path;
+  disk_mount_manager_->UnmountPath(
+      mount_path, chromeos::UNMOUNT_OPTIONS_NONE,
+      base::Bind(
+          &VolumeManager::OnExternalStorageDisabledChangedUnmountCallback,
+          weak_ptr_factory_.GetWeakPtr()));
+}
+
 void VolumeManager::OnExternalStorageDisabledChanged() {
   // If the policy just got disabled we have to unmount every device currently
   // mounted. The opposite is fine - we can let the user re-plug their device to
   // make it available.
   if (profile_->GetPrefs()->GetBoolean(prefs::kExternalStorageDisabled)) {
     // We do not iterate on mount_points directly, because mount_points can
     // be changed by UnmountPath().
     // TODO(hidehiko): Is it necessary to unmount mounted archives, too, here?
-    while (!disk_mount_manager_->mount_points().empty()) {
-      std::string mount_path =
-          disk_mount_manager_->mount_points().begin()->second.mount_path;
-      disk_mount_manager_->UnmountPath(
-          mount_path,
-          chromeos::UNMOUNT_OPTIONS_NONE,
-          chromeos::disks::DiskMountManager::UnmountPathCallback());
-    }
+    if (disk_mount_manager_->mount_points().empty())
+      return;
+    const std::string& mount_path =
+        disk_mount_manager_->mount_points().begin()->second.mount_path;
+    disk_mount_manager_->UnmountPath(
+        mount_path, chromeos::UNMOUNT_OPTIONS_NONE,
+        base::Bind(
+            &VolumeManager::OnExternalStorageDisabledChangedUnmountCallback,
+            weak_ptr_factory_.GetWeakPtr()));
   }
 }
 
 void VolumeManager::OnRemovableStorageAttached(
     const storage_monitor::StorageInfo& info) {
   if (!storage_monitor::StorageInfo::IsMTPDevice(info.device_id()))
     return;
   if (profile_->GetPrefs()->GetBoolean(prefs::kExternalStorageDisabled))
     return;
 
@@ skipping 176 matching lines @@
   if (mounted_volumes_.find(volume->volume_id()) == mounted_volumes_.end())
     return;
   if (error_code == chromeos::MOUNT_ERROR_NONE)
     mounted_volumes_.erase(volume->volume_id());
 
   FOR_EACH_OBSERVER(VolumeManagerObserver, observers_,
                     OnVolumeUnmounted(error_code, *volume.get()));
 }
 
 }  // namespace file_manager