Delete blimp/helium and remove references to it from dependent targets

blimp/helium/result.h

-// Copyright 2016 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 BLIMP_HELIUM_RESULT_H_
-#define BLIMP_HELIUM_RESULT_H_
-
-#include "blimp/helium/blimp_helium_export.h"
-
-namespace blimp {
-namespace helium {
-
-// Defines the canonical list of Helium result codes.
-// Result::OK is the only non-error code.
-// All other codes are considered errors and are prefixed by ERR_.
-// See error_list.h for the unprefixed list of error codes.
-//
-// (Approach is inspired by net/base/net_errors.h)
-enum Result {
-  SUCCESS,
-#define HELIUM_ERROR(label, value) ERR_##label = value,
-#include "blimp/helium/errors.h"
-#undef HELIUM_ERROR
-};
-
-// Gets a human-readable string representation of |result|.
-BLIMP_HELIUM_EXPORT const char* ResultToString(Result result);
-
-}  // namespace helium
-}  // namespace blimp
-
-#endif  // BLIMP_HELIUM_RESULT_H_