Let pyauto create an attached webdriver instance to manipulate web pages.

chrome/test/webdriver/session.cc

 // Copyright (c) 2011 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/webdriver/session.h"
 
 #include <sstream>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 59 matching lines @@
       implicit_wait_(0),
       has_alert_prompt_text_(false),
       options_(options) {
   SessionManager::GetInstance()->Add(this);
 }
 
 Session::~Session() {
   SessionManager::GetInstance()->Remove(id_);
 }
 
-Error* Session::Init(const FilePath& browser_exe,
-                     const FilePath& user_data_dir,
-                     const CommandLine& options) {
+Error* Session::Init(const Automation::BrowserOptions& options) {
   if (!thread_.Start()) {
     delete this;
     return new Error(kUnknownError, "Cannot start session thread");
   }
 
   Error* error = NULL;
   RunSessionTask(NewRunnableMethod(
       this,
       &Session::InitOnSessionThread,
-      browser_exe,
-      user_data_dir,
       options,
       &error));
   if (error)
     Terminate();
   return error;
 }
 
 Error* Session::BeforeExecuteCommand() {
   Error* error = NULL;
   if (!options_.load_async) {
@@ skipping 1013 matching lines @@
   done_event.Wait();
 }
 
 void Session::RunSessionTaskOnSessionThread(Task* task,
                                             base::WaitableEvent* done_event) {
   task->Run();
   delete task;
   done_event->Signal();
 }
 
-void Session::InitOnSessionThread(const FilePath& browser_exe,
-                                  const FilePath& user_data_dir,
-                                  const CommandLine& options,
+
+void Session::InitOnSessionThread(const Automation::BrowserOptions& options,
                                   Error** error) {
   automation_.reset(new Automation());
-  if (browser_exe.empty()) {
-    automation_->Init(options, user_data_dir, error);
-  } else {
-    automation_->InitWithBrowserPath(
-        browser_exe, user_data_dir, options, error);
-  }
-
+  automation_->Init(options, error);
   if (*error)
     return;
 
   std::vector<int> tab_ids;
   automation_->GetTabIds(&tab_ids, error);
   if (*error)
     return;
   if (tab_ids.empty()) {
     *error = new Error(kUnknownError, "No tab ids after initialization");
     return;
@@ skipping 342 matching lines @@
       path,
       &error));
   if (error)
     return error;
   if (!file_util::ReadFileToString(path, png))
     return new Error(kUnknownError, "Could not read screenshot file");
   return NULL;
 }
 
 }  // namespace webdriver