Move common ImageFetcher component files to core/

components/image_fetcher/request_metadata.h

-// Copyright 2017 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 COMPONENTS_IMAGE_FETCHER_REQUEST_METADATA_H_
-#define COMPONENTS_IMAGE_FETCHER_REQUEST_METADATA_H_
-
-#include <string>
-
-#include "net/url_request/url_fetcher.h"
-
-namespace image_fetcher {
-
-// Metadata for a URL request.
-struct RequestMetadata {
-  // Impossible http response code. Used to signal that no http response code
-  // was received.
-  enum ResponseCode {
-    RESPONSE_CODE_INVALID = net::URLFetcher::RESPONSE_CODE_INVALID
-  };
-
-  RequestMetadata();
-
-  std::string mime_type;
-  int http_response_code;
-  bool from_http_cache;
-};
-
-bool operator==(const RequestMetadata& lhs, const RequestMetadata& rhs);
-bool operator!=(const RequestMetadata& lhs, const RequestMetadata& rhs);
-
-}  // namespace image_fetcher
-
-#endif  // COMPONENTS_IMAGE_FETCHER_REQUEST_METADATA_H_