DevTools: handle devtools renderer unresponsiveness during beforeunload event interception

This patch fixes the crash which happenes under the following conditions:
1. DevTools window is in undocked state
2. DevTools renderer is unresponsive
3. User attempts to close inspected page

BUG=322380

Review URL: https://codereview.chromium.org/84883002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237611 0039d316-1c4b-4281-b951-d872f2087c98
DictionaryValue* CreateFileSystemValue(
    DevToolsFileHelper::FileSystem file_system) {
  DictionaryValue* file_system_value = new DictionaryValue();
  file_system_value->SetString("fileSystemName", file_system.file_system_name);
  file_system_value->SetString("rootURL", file_system.root_url);
  file_system_value->SetString("fileSystemPath", file_system.file_system_path);
  return file_system_value;
}

DictionaryValue* CreateFileSystemValue(
    DevToolsFileHelper::FileSystem file_system) {
  DictionaryValue* file_system_value = new DictionaryValue();
  file_system_value->SetString("fileSystemName", file_system.file_system_name);
  file_system_value->SetString("rootURL", file_system.root_url);
  file_system_value->SetString("fileSystemPath", file_system.file_system_path);
  return file_system_value;
}
