Use ExtractDrivePath(path()) instead of virtual_path() for getting Drive path.

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"
 #include "base/platform_file.h"
 #include "chrome/browser/chromeos/drive/drive_file_error.h"
 #include "chrome/browser/google_apis/gdata_errorcode.h"
 #include "googleurl/src/gurl.h"
+#include "webkit/fileapi/file_system_url.h"
 
 class Profile;
 
 namespace base {
 class FilePath;
 }
 
 namespace drive {
 
 class PlatformFileInfoProto;
@@ skipping 80 matching lines @@
 // migrated to the new namespace. http://crbug.com/174233.
 bool NeedsNamespaceMigration(const base::FilePath& path);
 
 // Returns new FilePath with a namespace "root" inserted at the 3rd component.
 // e.g. "/special/drive/root/dir" for "/special/drive/dir".
 // NeedsNamespaceMigration(path) should be true (after the TODOs are resolved).
 base::FilePath ConvertToMyDriveNamespace(const base::FilePath& path);
 
 // Extracts the Drive path from the given path located under the Drive mount
 // point. Returns an empty path if |path| is not under the Drive mount point.
-// Examples: ExtractGDatPath("/special/drive/foo.txt") => "drive/foo.txt"
+// Examples: ExtractDrivePath("/special/drive/foo.txt") => "drive/foo.txt"
 base::FilePath ExtractDrivePath(const base::FilePath& path);
 
+// Extracts the Drive path (e.g., "drive/foo.txt") from the filesystem URL.
+// Returns an empty path if |url| does not point under Drive mount point.
+base::FilePath ExtractDrivePathFromFileSystemUrl(
+    const fileapi::FileSystemURL& url);
+
 // Escapes a file name in Drive cache.
 // Replaces percent ('%'), period ('.') and slash ('/') with %XX (hex)
 std::string EscapeCacheFileName(const std::string& filename);
 
 // Unescapes a file path in Drive cache.
 // This is the inverse of EscapeCacheFileName.
 std::string UnescapeCacheFileName(const std::string& filename);
 
 // Escapes forward slashes from file names with magic unicode character
 // \u2215 pretty much looks the same in UI.
@@ skipping 67 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_