Do not create a new directory database for read operations.

webkit/fileapi/obfuscated_file_system_file_util.h

 // Copyright (c) 2011 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 WEBKIT_FILEAPI_OBFUSCATED_FILE_SYSTEM_FILE_UTIL_H_
 #define WEBKIT_FILEAPI_OBFUSCATED_FILE_SYSTEM_FILE_UTIL_H_
 
 #include <map>
 #include <vector>
 
@@ skipping 30 matching lines @@
 // SandboxMountPointProvider [and the task it uses to drop the reference] and
 // SandboxMountPointProvider::GetFileSystemRootPathTask.  Without that last one,
 // we wouldn't need ref counting.
 //
 // TODO(ericu): We don't ever update directory mtimes; which operations should
 // do that?
 class ObfuscatedFileSystemFileUtil : public FileSystemFileUtil,
     public base::RefCountedThreadSafe<ObfuscatedFileSystemFileUtil> {
  public:
 
-  ObfuscatedFileSystemFileUtil(const FilePath& file_system_directory);
+  explicit ObfuscatedFileSystemFileUtil(const FilePath& file_system_directory);
   virtual ~ObfuscatedFileSystemFileUtil();
 
   virtual base::PlatformFileError CreateOrOpen(
       FileSystemOperationContext* context,
       const FilePath& file_path,
       int file_flags,
       base::PlatformFile* file_handle,
       bool* created) OVERRIDE;
 
   virtual base::PlatformFileError EnsureFileExists(
@@ skipping 143 matching lines @@
       const FilePath& virtual_path);
   // This converts from a relative path [as is stored in the FileInfo.data_path
   // field] to an absolute local path that can be given to the operating system.
   // It does no checks as to whether the file actually exists; it's pure path
   // manipulation.
   FilePath DataPathToLocalPath(
       const GURL& origin, FileSystemType type, const FilePath& data_path);
   // This does the reverse of DataPathToLocalPath.
   FilePath LocalPathToDataPath(
       const GURL& origin, FileSystemType type, const FilePath& local_path);
+  // This returns NULL if |create| flag is false and a filesystem does not
+  // exist for the given |origin_url| and |type|.
+  // For read operations |create| should be false.
   FileSystemDirectoryDatabase* GetDirectoryDatabase(
-      const GURL& origin_url, FileSystemType type);
+      const GURL& origin_url, FileSystemType type, bool create);
   void MarkUsed();
   void DropDatabases();
   bool DestroyDirectoryDatabase(const GURL& origin, FileSystemType type);
   bool InitOriginDatabase(bool create);
 
   typedef std::map<std::string, FileSystemDirectoryDatabase*> DirectoryMap;
   DirectoryMap directories_;
   scoped_ptr<FileSystemOriginDatabase> origin_database_;
   FilePath file_system_directory_;
   base::OneShotTimer<ObfuscatedFileSystemFileUtil> timer_;
 
   DISALLOW_COPY_AND_ASSIGN(ObfuscatedFileSystemFileUtil);
 };
 
 }  // namespace fileapi
 
 #endif  // WEBKIT_FILEAPI_OBFUSCATED_FILE_SYSTEM_FILE_UTIL_H_