Implementation of beginning of Declarative Web Request API backend

chrome/browser/extensions/api/declarative_webrequest/request_stages.h

+// Copyright (c) 2012 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 CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_WEBREQUEST_REQUEST_STAGES_H_
+#define CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_WEBREQUEST_REQUEST_STAGES_H_
+#pragma once
+
+namespace extensions {
+
+// The stages of the web request during which a condition can be tested and
+// an action can be applied. This is required because for example the response
+// headers cannot be tested before a request has been sent.
+enum RequestStages {
+  ON_BEFORE_REQUEST = 1 << 0,
+  ON_BEFORE_SEND_HEADERS = 1 << 1,
+  ON_SEND_HEADERS = 1 << 2,
+  ON_HEADERS_RECEIVED = 1 << 3,
+  ON_AUTH_REQUIRED = 1 << 4,
+  ON_BEFORE_REDIRECT = 1 << 5,
+  ON_RESPONSE_STARTED = 1 << 6,
+  ON_COMPLETED = 1 << 7,
+  ON_ERROR = 1 << 8
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_WEBREQUEST_REQUEST_STAGES_H_