[ChromeDriver] Support mobile emulation on desktop Chrome.

chrome/test/chromedriver/chrome/device_metrics_override_manager.cc

+// Copyright (c) 2014 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 "base/values.h"
+#include "chrome/test/chromedriver/chrome/device_metrics.h"
+#include "chrome/test/chromedriver/chrome/device_metrics_override_manager.h"
+#include "chrome/test/chromedriver/chrome/devtools_client.h"
+#include "chrome/test/chromedriver/chrome/status.h"
+
+DeviceMetricsOverrideManager::DeviceMetricsOverrideManager(DevToolsClient* client)
+    : client_(client) {
+  client_->AddListener(this);
+}
+
+DeviceMetricsOverrideManager::~DeviceMetricsOverrideManager() {
+}
+
+Status DeviceMetricsOverrideManager::OverrideDeviceMetrics(
+    const DeviceMetrics& device_metrics) {
+  overridden_device_metrics_.reset(new DeviceMetrics(device_metrics));
+  return ApplyOverrideIfNeeded();
+}
+
+Status DeviceMetricsOverrideManager::OnConnected(DevToolsClient* client) {
+  return ApplyOverrideIfNeeded();
+}
+
+Status DeviceMetricsOverrideManager::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 DeviceMetricsOverrideManager::ApplyOverrideIfNeeded() {
+  if (!overridden_device_metrics_)
+    return Status(kOk);
+
+  base::DictionaryValue params;
+  params.SetInteger("width", overridden_device_metrics_->width);
+  params.SetInteger("height", overridden_device_metrics_->height);
+  params.SetDouble("deviceScaleFactor", overridden_device_metrics_->device_scale_factor);
+  params.SetBoolean("emulateViewport", overridden_device_metrics_->emulate_viewport);
+  params.SetBoolean("fitWindow", overridden_device_metrics_->fit_window);
+  params.SetBoolean("textAutosizing", overridden_device_metrics_->text_autosizing);
+  params.SetDouble("fontScaleFactor", overridden_device_metrics_->font_scale_factor);
+  return client_->SendCommand("Page.setDeviceMetricsOverride", params);
+}