Adds removable-drive listing for OS X.

chrome/browser/extensions/api/image_writer_private/removable_storage_provider_linux.cc

Index: chrome/browser/extensions/api/image_writer_private/removable_storage_provider_linux.cc
diff --git a/chrome/browser/extensions/api/image_writer_private/removable_storage_provider_linux.cc b/chrome/browser/extensions/api/image_writer_private/removable_storage_provider_linux.cc
index 34c1c89fcedb567808b4602148357be55c3bc581..7b14c27477e758f58051ef33634a0d3ab1d14741 100644
--- a/chrome/browser/extensions/api/image_writer_private/removable_storage_provider_linux.cc
+++ b/chrome/browser/extensions/api/image_writer_private/removable_storage_provider_linux.cc
@@ -41,8 +41,9 @@ static int get_device_blk_size(const std::string& path) {
   return blk_size;
 }
 
-bool RemovableStorageProvider::PopulateDeviceList(
-    scoped_refptr<StorageDeviceList> device_list) {
+void RemovableStorageProvider::GetAllDevicesImpl(
+    const DeviceListReadyCallback& callback) {
+  scoped_refptr<StorageDeviceList> device_list(new StorageDeviceList);
   struct udev* udev;
   struct udev_enumerate* enumerate;
   struct udev_list_entry* devices, *dev_list_entry;
@@ -51,7 +52,8 @@ bool RemovableStorageProvider::PopulateDeviceList(
   udev = udev_new();
   if (!udev) {
     DLOG(ERROR) << "Can't create udev";
-    return false;
+    callback.Run(device_list, false);
+    return;
   }
 
   /* Create a list of the devices in the 'block' subsystem. */
@@ -106,7 +108,7 @@ bool RemovableStorageProvider::PopulateDeviceList(
   udev_enumerate_unref(enumerate);
   udev_unref(udev);
 
-  return true;
+  callback.Run(device_list, true);
 }
 
 } // namespace extensions