Implement ResourceQueue, an object that makes it easy to delay starting

chrome/browser/renderer_host/global_request_id.h

+// Copyright (c) 2009 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_RENDERER_HOST_GLOBAL_REQUEST_ID_H_
+#define CHROME_BROWSER_RENDERER_HOST_GLOBAL_REQUEST_ID_H_
+
+// Uniquely identifies a URLRequest.
+struct GlobalRequestID {
+  GlobalRequestID() : child_id(-1), request_id(-1) {
+  }
+
+  GlobalRequestID(int child_id, int request_id)
+      : child_id(child_id),
+        request_id(request_id) {
+  }
+
+  // The unique ID of the child process (different from OS's PID).
+  int child_id;
+
+  // The request ID (unique for the child).
+  int request_id;
+
+  bool operator<(const GlobalRequestID& other) const {
+    if (child_id == other.child_id)
+      return request_id < other.request_id;
+    return child_id < other.child_id;
+  }
+};
+
+#endif  // CHROME_BROWSER_RENDERER_HOST_GLOBAL_REQUEST_ID_H_