[chromedriver] Add Network Conditions Override Manager and tests

chrome/test/chromedriver/chrome/network_conditions_override_manager.cc

Index: chrome/test/chromedriver/chrome/network_conditions_override_manager.cc
diff --git a/chrome/test/chromedriver/chrome/network_conditions_override_manager.cc b/chrome/test/chromedriver/chrome/network_conditions_override_manager.cc
new file mode 100644
index 0000000000000000000000000000000000000000..18c90187939a73f6317e7dfd6ea42a00d030fa34
--- /dev/null
+++ b/chrome/test/chromedriver/chrome/network_conditions_override_manager.cc
@@ -0,0 +1,76 @@
+// 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.
+
+#include "chrome/test/chromedriver/chrome/network_conditions_override_manager.h"
+
+#include "base/values.h"
+#include "chrome/test/chromedriver/chrome/devtools_client.h"
+#include "chrome/test/chromedriver/chrome/network_conditions.h"
+#include "chrome/test/chromedriver/chrome/status.h"
+
+NetworkConditionsOverrideManager::NetworkConditionsOverrideManager(
+    DevToolsClient* client)
+    : client_(client),
+      overridden_network_conditions_(NULL) {
+  client_->AddListener(this);
+}
+
+NetworkConditionsOverrideManager::~NetworkConditionsOverrideManager() {
+}
+
+Status NetworkConditionsOverrideManager::OverrideNetworkConditions(
+    const NetworkConditions& network_conditions) {
+  Status status = ApplyOverride(&network_conditions);
+  if (status.IsOk())
+    overridden_network_conditions_ = &network_conditions;
+  return status;
+}
+
+Status NetworkConditionsOverrideManager::OnConnected(DevToolsClient* client) {
+  return ApplyOverrideIfNeeded();
+}
+
+Status NetworkConditionsOverrideManager::OnEvent(
+    DevToolsClient* client,
+    const std::string& method,
+    const base::DictionaryValue& params) {
+  if (method == "Page.frameNavigated") {
+    const base::Value* unused_value;
+    if (!params.Get("frame.parentId", &unused_value))
+      return ApplyOverrideIfNeeded();
+  }
+  return Status(kOk);
+}
+
+Status NetworkConditionsOverrideManager::ApplyOverrideIfNeeded() {
+  if (overridden_network_conditions_)
+    return ApplyOverride(overridden_network_conditions_);
+  return Status(kOk);
+}
+
+Status NetworkConditionsOverrideManager::ApplyOverride(
+    const NetworkConditions* network_conditions) {
+  base::DictionaryValue params, empty_params;
+  params.SetBoolean("offline", network_conditions->offline);
+  params.SetDouble("latency", network_conditions->latency);
+  params.SetDouble("downloadThroughput",
+                    network_conditions->download_throughput);
+  params.SetDouble("uploadThroughput", network_conditions->upload_throughput);
+
+  Status status = client_->SendCommand("Network.enable", empty_params);
+  if (status.IsError())
+    return status;
+
+  scoped_ptr<base::DictionaryValue> result;
+  bool can = false;
+  status = client_->SendCommandAndGetResult(
+      "Network.canEmulateNetworkConditions", empty_params, &result);
+  if (status.IsError() || !result->GetBoolean("result", &can))
+    return Status(kUnknownError,
+        "unable to detect if chrome can emulate network conditions", status);
+  if (!can)
+    return Status(kUnknownError, "Cannot emulate network conditions");
+
+  return client_->SendCommand("Network.emulateNetworkConditions", params);
+}