(2nd try) Add a helper class that keeps per-profile information for FileSystem API

chrome/browser/file_system/file_system_host_context.h

+// Copyright (c) 2010 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_FILE_SYSTEM_FILE_SYSTEM_HOST_CONTEXT_H_
+#define CHROME_BROWSER_FILE_SYSTEM_FILE_SYSTEM_HOST_CONTEXT_H_
+
+#include "base/file_path.h"
+#include "base/ref_counted.h"
+#include "base/scoped_ptr.h"
+#include "googleurl/src/gurl.h"
+#include "third_party/WebKit/WebKit/chromium/public/WebFileSystem.h"
+
+// This is owned by profile and shared by all the FileSystemDispatcherHost
+// that shared by the same profile.
+class FileSystemHostContext
+    : public base::RefCountedThreadSafe<FileSystemHostContext> {
+ public:
+  FileSystemHostContext(const FilePath& data_path, bool is_incognito);
+  const FilePath& base_path() const { return base_path_; }
+  bool is_incognito() const { return is_incognito_; }
+
+  // Returns the root path and name for the file system specified by given
+  // |origin_url| and |type|.  Returns true if the file system is available
+  // for the profile and |root_path| and |name| are filled successfully.
+  bool GetFileSystemRootPath(
+      const GURL& origin_url,
+      WebKit::WebFileSystem::Type type,
+      FilePath* root_path,
+      std::string* name) const;
+
+  // Check if the given |path| is in the FileSystem base directory.
+  bool CheckValidFileSystemPath(const FilePath& path) const;
+
+  // Returns the storage identifier string for the given |url|.
+  static std::string GetStorageIdentifierFromURL(const GURL& url);
+
+  // The FileSystem directory name.
+  static const FilePath::CharType kFileSystemDirectory[];
+
+  static const char kPersistentName[];
+  static const char kTemporaryName[];
+
+ private:
+  const FilePath base_path_;
+  const bool is_incognito_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(FileSystemHostContext);
+};
+
+#endif  // CHROME_BROWSER_FILE_SYSTEM_FILE_SYSTEM_HOST_CONTEXT_H_