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

chrome/test/automation/proxy_launcher.h

 // 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.
 
 #ifndef CHROME_TEST_AUTOMATION_PROXY_LAUNCHER_H_
 #define CHROME_TEST_AUTOMATION_PROXY_LAUNCHER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 47 matching lines @@
 
     // If true, the window is shown. Otherwise it is hidden.
     bool show_window;
   };
 
   ProxyLauncher();
 
   virtual ~ProxyLauncher();
 
   // Launches the browser if needed and establishes a connection with it.
-  virtual void InitializeConnection(const LaunchState& state,
-                                    bool wait_for_initial_loads) = 0;
+  // Returns true on success.
+  virtual bool InitializeConnection(
+      const LaunchState& state,
+      bool wait_for_initial_loads) WARN_UNUSED_RESULT = 0;
 
   // Shuts down the browser if needed and destroys any
   // connections established by InitalizeConnection.
   virtual void TerminateConnection() = 0;
 
   // Launches the browser and IPC testing connection in server mode.
   // Returns true on success.
   bool LaunchBrowserAndServer(const LaunchState& state,
                               bool wait_for_initial_loads) WARN_UNUSED_RESULT;
 
@@ skipping 201 matching lines @@
 // to a browser process that is already running.
 // The channel id of the proxy is a constant specified by kInterfacePath.
 class NamedProxyLauncher : public ProxyLauncher {
  public:
   // If launch_browser is true, launches Chrome with named interface enabled.
   // Otherwise, there should be an existing instance the proxy can connect to.
   NamedProxyLauncher(const std::string& channel_id,
                      bool launch_browser, bool disconnect_on_failure);
 
   virtual AutomationProxy* CreateAutomationProxy(int execution_timeout);
-  virtual void InitializeConnection(const LaunchState& state,
-                                    bool wait_for_initial_loads);
+  virtual bool InitializeConnection(
+      const LaunchState& state,
+      bool wait_for_initial_loads) OVERRIDE WARN_UNUSED_RESULT;
   virtual void TerminateConnection();
   virtual std::string PrefixedChannelID() const;
 
  protected:
   std::string channel_id_;      // Channel id of automation proxy.
   bool launch_browser_;         // True if we should launch the browser too.
   bool disconnect_on_failure_;  // True if we disconnect on IPC channel failure.
 
  private:
   DISALLOW_COPY_AND_ASSIGN(NamedProxyLauncher);
 };
 
 // Uses an automation proxy that communicates over an anonymous socket.
 class AnonymousProxyLauncher : public ProxyLauncher {
  public:
   explicit AnonymousProxyLauncher(bool disconnect_on_failure);
   virtual AutomationProxy* CreateAutomationProxy(int execution_timeout);
-  virtual void InitializeConnection(const LaunchState& state,
-                                    bool wait_for_initial_loads);
+  virtual bool InitializeConnection(
+      const LaunchState& state,
+      bool wait_for_initial_loads) OVERRIDE WARN_UNUSED_RESULT;
   virtual void TerminateConnection();
   virtual std::string PrefixedChannelID() const;
 
  protected:
   std::string channel_id_;      // Channel id of automation proxy.
   bool disconnect_on_failure_;  // True if we disconnect on IPC channel failure.
 
  private:
   DISALLOW_COPY_AND_ASSIGN(AnonymousProxyLauncher);
 };
 
 #endif  // CHROME_TEST_AUTOMATION_PROXY_LAUNCHER_H_