message: Manage Expected in formatting APIs
diff: #include "clang_format.h"
  +#include <loguru.hpp>
  +
  using namespace clang::format;
  using namespace clang::tooling;
  @@ -27,12 +29,18 @@ std::vector<Replacement> ClangFormat::FormatWholeDocument() {
  const auto language_kind = getLanguageKindFromFilename(document_filename_);
  FormatStyle predefined_style;
  getPredefinedStyle("chromium", language_kind, &predefined_style);
  - auto style = getStyle("file", document_filename_, "chromium");
  - if (style == predefined_style) {
  - style.UseTab = insert_spaces_ ? FormatStyle::UseTabStyle::UT_Never
  + llvm::Expected<FormatStyle> style =
  + getStyle("file", document_filename_, "chromium");
  + if (!style) {
  + LOG_S(ERROR) << llvm::toString(style.takeError());
  + return {};
  + }
  +
  + if (*style == predefined_style) {
  + style->UseTab = insert_spaces_ ? FormatStyle::UseTabStyle::UT_Never
  : FormatStyle::UseTabStyle::UT_Always;
  - style.IndentWidth = tab_size_;
  + style->IndentWidth = tab_size_;
  }
  - auto format_result = reformat(style, document_, ranges_, document_filename_);
  + auto format_result = reformat(*style, document_, ranges_, document_filename_);
  return std::vector<Replacement>(format_result.begin(), format_result.end());
  }
  