AppShell: Enable chrome.fileSystem.retainEntry/restoreEntry

extensions/shell/browser/shell_extensions_api_client.cc

 // 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.
 
 #include "extensions/shell/browser/shell_extensions_api_client.h"
 
 #include "base/memory/ptr_util.h"
 #include "extensions/shell/browser/delegates/shell_kiosk_delegate.h"
 #include "extensions/shell/browser/shell_app_view_guest_delegate.h"
 #include "extensions/shell/browser/shell_extension_web_contents_observer.h"
 #include "extensions/shell/browser/shell_virtual_keyboard_delegate.h"
 
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+#include "extensions/shell/browser/api/file_system/shell_file_system_delegate.h"
+#endif
+
 namespace extensions {
 
-ShellExtensionsAPIClient::ShellExtensionsAPIClient() {
-}
+ShellExtensionsAPIClient::ShellExtensionsAPIClient() {}
+
+ShellExtensionsAPIClient::~ShellExtensionsAPIClient() {}
 
 void ShellExtensionsAPIClient::AttachWebContentsHelpers(
     content::WebContents* web_contents) const {
   ShellExtensionWebContentsObserver::CreateForWebContents(web_contents);
 }
 
 AppViewGuestDelegate* ShellExtensionsAPIClient::CreateAppViewGuestDelegate()
     const {
   return new ShellAppViewGuestDelegate();
 }
 
 std::unique_ptr<VirtualKeyboardDelegate>
 ShellExtensionsAPIClient::CreateVirtualKeyboardDelegate() const {
   return base::MakeUnique<ShellVirtualKeyboardDelegate>();
 }
 
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+FileSystemDelegate* ShellExtensionsAPIClient::GetFileSystemDelegate() {
+  if (!file_system_delegate_)
+    file_system_delegate_ = base::MakeUnique<ShellFileSystemDelegate>();
+  return file_system_delegate_.get();
+}
+#endif
+
 }  // namespace extensions