Rename FilePath -> base::FilePath in various toplevel directories

ash/test/test_suite_init.mm

 // 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.
 
 #include "ash/test/test_suite_init.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/file_path.h"
 #include "base/mac/bundle_locations.h"
 #include "base/memory/scoped_nsobject.h"
 #include "base/path_service.h"
 
 namespace ash {
 namespace test {
 
 void OverrideFrameworkBundle() {
   // Look in the AuraShell.app directory for resources.
-  FilePath path;
+  base::FilePath path;
   PathService::Get(base::DIR_EXE, &path);
   path = path.Append(FILE_PATH_LITERAL("AuraShell.app"));
   base::mac::SetOverrideFrameworkBundlePath(path);
 }
 
 }  // namespace test
 }  // namespace ash