drive: Use "/drive/root" namespace and fix Files app and tests.

chrome/browser/chromeos/drive/drive_file_system_util.h

 // Copyright (c) 2012 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_UTIL_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_UTIL_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
@@ skipping 41 matching lines @@
 // are used in URLs for the file manager, hence user-visible.
 const base::FilePath::CharType kDriveGrandRootDirName[] =
     FILE_PATH_LITERAL("drive");
 
 const base::FilePath::CharType kDriveMyDriveRootDirName[] =
     FILE_PATH_LITERAL("root");
 
 const base::FilePath::CharType kDriveOtherDirName[] =
     FILE_PATH_LITERAL("other");
 
-// TODO(haruki): Change this to "drive/root" in order to use separate namespace.
-// http://crbug.com/174233
 const base::FilePath::CharType kDriveMyDriveRootPath[] =
-    FILE_PATH_LITERAL("drive");
+    FILE_PATH_LITERAL("drive/root");
 
 const base::FilePath::CharType kDriveOtherDirPath[] =
     FILE_PATH_LITERAL("drive/other");
 
 // Returns the path of the top root of the pseudo tree.
 const base::FilePath& GetDriveGrandRootPath();
 
 // Returns the path of the directory representing "My Drive".
 const base::FilePath& GetDriveMyDriveRootPath();
 
@@ skipping 120 matching lines @@
   void operator()(T* object) const {
     if (object)
       object->Destroy();
   }
 };
 
 }  // namespace util
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_UTIL_H_