[ChromeDriver] Support mobile emulation on desktop Chrome.

chrome/test/chromedriver/session_commands.cc

 // Copyright (c) 2013 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/session_commands.h"
 
 #include <list>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 81 matching lines @@
   if (chrome->GetAsDesktop()) {
     chrome_caps->SetString(
         "userDataDir",
         chrome->GetAsDesktop()->command().GetSwitchValueNative(
             "user-data-dir"));
   }
   caps->Set("chrome", chrome_caps.release());
   return caps.Pass();
 }
 
+Status InitDeviceMetricsOverride(
+    Session* session,
+    DeviceMetrics* device_metrics)
+{
+  WebView* web_view;
+  session->chrome->GetWebViewById(session->window, &web_view);
+  Status status = web_view->OverrideDeviceMetrics(*device_metrics);
+  if (status.IsOk())
+    session->overridden_device_metrics.reset(new DeviceMetrics(*device_metrics));
+  return status;
+}
 
 Status InitSessionHelper(
     const InitSessionParams& bound_params,
     Session* session,
     const base::DictionaryValue& params,
     scoped_ptr<base::Value>* value) {
   session->driver_log.reset(
       new WebDriverLog(WebDriverLog::kDriverType, Log::kAll));
   const base::DictionaryValue* desired_caps;
   if (!params.GetDictionary("desiredCapabilities", &desired_caps))
@@ skipping 30 matching lines @@
     return status;
 
   std::list<std::string> web_view_ids;
   status = session->chrome->GetWebViewIds(&web_view_ids);
   if (status.IsError() || web_view_ids.empty()) {
     return status.IsError() ? status :
         Status(kUnknownError, "unable to discover open window in chrome");
   }
 
   session->window = web_view_ids.front();
+
+  if (capabilities.device_metrics.width != 0) {

[stgao, 2014/05/03 00:15:20]

Instead of creating an instance of struct |device_metrics| in capabilities.h, we
could wrap it up with a scoped_ptr.

In this way, we could test the scoped_ptr to check if an emulation is requested.

[sam.rawlins, 2014/05/06 23:51:46]

Done.

+    InitDeviceMetricsOverride(session, &capabilities.device_metrics);
+  }
+
   session->detach = capabilities.detach;
   session->force_devtools_screenshot = capabilities.force_devtools_screenshot;
   session->capabilities = CreateCapabilities(session->chrome.get());
   value->reset(session->capabilities->DeepCopy());
   return Status(kOk);
 }
 
 }  // namespace
 
 Status ExecuteInitSession(
@@ skipping 482 matching lines @@
 Status ExecuteSetAutoReporting(
     Session* session,
     const base::DictionaryValue& params,
     scoped_ptr<base::Value>* value) {
   bool enabled;
   if (!params.GetBoolean("enabled", &enabled))
     return Status(kUnknownError, "missing parameter 'enabled'");
   session->auto_reporting_enabled = enabled;
   return Status(kOk);
 }