[chromedriver] Add Network Conditions Override Manager and tests

chrome/test/chromedriver/chrome/network_conditions_override_manager.h

+// Copyright (c) 2015 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_TEST_CHROMEDRIVER_CHROME_NETWORK_CONDITIONS_OVERRIDE_MANAGER_H_
+#define CHROME_TEST_CHROMEDRIVER_CHROME_NETWORK_CONDITIONS_OVERRIDE_MANAGER_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/test/chromedriver/chrome/devtools_event_listener.h"
+
+namespace base {
+class DictionaryValue;
+}
+
+class DevToolsClient;
+struct NetworkConditions;
+class Status;
+
+// Overrides the network conditions, if requested, for the duration of the
+// given |DevToolsClient|'s lifetime.
+class NetworkConditionsOverrideManager : public DevToolsEventListener {
+ public:
+  explicit NetworkConditionsOverrideManager(DevToolsClient* client);
+  ~NetworkConditionsOverrideManager() override;
+
+  Status OverrideNetworkConditions(const NetworkConditions& network_conditions);
+
+  // Overridden from DevToolsEventListener:
+  Status OnConnected(DevToolsClient* client) override;
+  Status OnEvent(DevToolsClient* client,
+                 const std::string& method,
+                 const base::DictionaryValue& params) override;
+
+ private:
+  Status ApplyOverrideIfNeeded();
+  Status ApplyOverride(const NetworkConditions* network_conditions);
+
+  DevToolsClient* client_;
+  const NetworkConditions* overridden_network_conditions_;
+
+  DISALLOW_COPY_AND_ASSIGN(NetworkConditionsOverrideManager);
+};
+
+#endif  // CHROME_TEST_CHROMEDRIVER_CHROME_NETWORK_CONDITIONS_OVERRIDE_MANAGER_H_