Don't show hidden devices in UI (exept from imageburner).

chrome/browser/chromeos/extensions/file_browser_event_router.cc

 // Copyright (c) 2011 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/extensions/file_browser_event_router.h"
 
 #include "base/json/json_writer.h"
 #include "base/message_loop.h"
 #include "base/stl_util.h"
 #include "base/values.h"
@@ skipping 137 matching lines @@
   iter->second->extensions.erase(extension_id);
   if (iter->second->extensions.empty()) {
     delete iter->second;
     file_watchers_.erase(iter);
   }
 }
 
 void ExtensionFileBrowserEventRouter::DiskChanged(
     chromeos::MountLibraryEventType event,
     const chromeos::MountLibrary::Disk* disk) {
+  // Disregard hidden devices.
+  if (disk->is_hidden())
+    return;
   if (event == chromeos::MOUNT_DISK_ADDED) {
     OnDiskAdded(disk);
   } else if (event == chromeos::MOUNT_DISK_REMOVED) {
     OnDiskRemoved(disk);
   }
 }
 
 void ExtensionFileBrowserEventRouter::DeviceChanged(
     chromeos::MountLibraryEventType event,
     const std::string& device_path) {
   if (event == chromeos::MOUNT_DEVICE_ADDED) {
     OnDeviceAdded(device_path);
   } else if (event == chromeos::MOUNT_DEVICE_REMOVED) {
     OnDeviceRemoved(device_path);
   } else if (event == chromeos::MOUNT_DEVICE_SCANNED) {
     OnDeviceScanned(device_path);
   } else if (event == chromeos::MOUNT_FORMATTING_STARTED) {
+  // TODO(tbarzic): get rid of '!'.
     if (device_path[0] == '!') {
       OnFormattingStarted(device_path.substr(1), false);
     } else {
       OnFormattingStarted(device_path, true);
     }
   } else if (event == chromeos::MOUNT_FORMATTING_FINISHED) {
     if (device_path[0] == '!') {
       OnFormattingFinished(device_path.substr(1), false);
     } else {
       OnFormattingFinished(device_path, true);
@@ skipping 270 matching lines @@
           &FileWatcherDelegate::HandleFileWatchOnUIThread,
           local_path,
           true));     // got_error
 }
 
 void
 ExtensionFileBrowserEventRouter::FileWatcherDelegate::HandleFileWatchOnUIThread(
      const FilePath& local_path, bool got_error) {
   router_->HandleFileWatchNotification(local_path, got_error);
 }