[Chromedriver] Add Device Metrics override support to ChromeDriver via Capabilities

chrome/test/chromedriver/chrome/mobile_emulation_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/devtools_client.h"
+#include "chrome/test/chromedriver/chrome/mobile_emulation_override_manager.h"
+#include "chrome/test/chromedriver/chrome/status.h"
+
+MobileEmulationOverrideManager::MobileEmulationOverrideManager(
+    DevToolsClient* client,
+    const DeviceMetrics* device_metrics)
+    : client_(client), overridden_device_metrics_(device_metrics) {
+  if (overridden_device_metrics_)
+    client_->AddListener(this);
+}
+
+MobileEmulationOverrideManager::~MobileEmulationOverrideManager() {
+}
+
+Status MobileEmulationOverrideManager::OnConnected(DevToolsClient* client) {
+  return ApplyOverrideIfNeeded();
+}
+
+Status MobileEmulationOverrideManager::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 MobileEmulationOverrideManager::ApplyOverrideIfNeeded() {
+  if (overridden_device_metrics_ == NULL)
+    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",

[pfeldman, 2014/05/20 18:57:29]

Note that you are using undocumented API that is a subject to change.

@dgozman: you were planning to rename this to 'mobile'. Are you sure you want to
do this? If yes, we could help via making it sooner.

[dgozman, 2014/05/20 19:01:40]

Yes, I want to do this to emphasize it's not only the viewport emulation, but
also some other mobile-only aspects like screen position or compositor tweaks in
the future. Feel free to do it sooner.

[srawlins, 2014/05/20 19:36:15]

@pfeldman, @dgozman: SGTM. We can update chromedriver to accept old and new name
once that change is written and part of chrome.

+                    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);
+}