Rename "CheckWritable" to "PrepareForWritableApp" to reflect the actual behavior.

chrome/browser/chromeos/file_manager/filesystem_api_util.h

 // 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.
 //
 // The file contains utility functions to implement chrome.fileSystem API for
 // file paths that do not directly map to host machine's file system path, such
 // as Google Drive or virtual volumes provided by fileSystemProvider extensions.
 
 #ifndef CHROME_BROWSER_CHROMEOS_FILE_MANAGER_FILESYSTEM_API_UTIL_H_
 #define CHROME_BROWSER_CHROMEOS_FILE_MANAGER_FILESYSTEM_API_UTIL_H_
@@ skipping 22 matching lines @@
     const base::FilePath& path,
     const base::Callback<void(bool, const std::string&)>& callback);
 
 // Checks whether the |path| points to a directory, and asynchronously sends
 // the result to |callback|.
 void IsNonNativeLocalPathDirectory(
     Profile* profile,
     const base::FilePath& path,
     const base::Callback<void(bool)>& callback);
 
-// Prepares a writable file at |path|, i.e., creates a file there if it didn't
-// exist, and asynchronously sends to |callback| whether it succeeded.
-void PrepareNonNativeLocalPathWritableFile(
+// Ensures a file exists at |path|, i.e., it does nothing if a file is already
+// present, or creates a file there if it isn't, and asynchronously sends to
+// |callback| whether it succeeded.
+void PrepareNonNativeLocalFileForWritableApp(
     Profile* profile,
     const base::FilePath& path,
     const base::Callback<void(bool)>& callback);
 
 }  // namespace util
 }  // namespace file_manager
 
 #endif  // CHROME_BROWSER_CHROMEOS_FILE_MANAGER_FILESYSTEM_API_UTIL_H_