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

chrome/browser/chromeos/drive/drive_file_system_util.cc

Index: chrome/browser/chromeos/drive/drive_file_system_util.cc
diff --git a/chrome/browser/chromeos/drive/drive_file_system_util.cc b/chrome/browser/chromeos/drive/drive_file_system_util.cc
index 0c8989d50d0a50803d5f9a6416ae9a202d85d879..885376bb9aedb9a3436bde692deda66e9d1e74bf 100644
--- a/chrome/browser/chromeos/drive/drive_file_system_util.cc
+++ b/chrome/browser/chromeos/drive/drive_file_system_util.cc
@@ -278,6 +278,13 @@ base::FilePath ExtractDrivePath(const base::FilePath& path) {
   return extracted;
 }
 
+base::FilePath ExtractDrivePathFromFileSystemUrl(
+    const fileapi::FileSystemURL& url) {
+  if (!url.is_valid() || url.type() != fileapi::kFileSystemTypeDrive)
+    return base::FilePath();
+  return ExtractDrivePath(url.path());
+}
+
 std::string EscapeCacheFileName(const std::string& filename) {
   // This is based on net/base/escape.cc: net::(anonymous namespace)::Escape
   std::string escaped;