[fsp] Decouple file_service_provider::Service.

chrome/browser/chromeos/file_system_provider/mount_path_util.cc

+// Copyright 2014 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_system_provider/mount_path_util.h"
+
+#include "base/files/file_path.h"
+#include "base/stl_util.h"
+#include "base/strings/string_number_conversions.h"
+#include "chrome/browser/chromeos/login/user.h"
+#include "chrome/browser/chromeos/login/user_manager.h"
+
+namespace chromeos {
+namespace file_system_provider {
+namespace util {
+
+namespace {
+
+// Root mount path for all of the provided file systems.
+const base::FilePath::CharType kProvidedMountPointRoot[] =
+    FILE_PATH_LITERAL("/provided");
+
+}  // namespace
+
+base::FilePath GetMountPointPath(Profile* profile,
+                                 std::string extension_id,
+                                 int file_system_id) {
+  chromeos::User* const user =
+      chromeos::UserManager::IsInitialized()
+          ? chromeos::UserManager::Get()->GetUserByProfile(
+                profile->GetOriginalProfile())
+          : NULL;
+  const std::string user_suffix = user ? "-" + user->username_hash() : "";
+  return base::FilePath(kProvidedMountPointRoot).AppendASCII(
+      extension_id + "-" + base::IntToString(file_system_id) + user_suffix);
+}
+
+}  // namespace util
+}  // namespace file_system_provider
+}  // namespace chromeos