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

chrome/test/automation/proxy_launcher.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/automation/proxy_launcher.h"
 
 #include "base/environment.h"
 #include "base/file_util.h"
 #include "base/string_number_conversions.h"
 #include "base/string_split.h"
@@ skipping 481 matching lines @@
   return browser_launch_time_;
 }
 
 base::TimeDelta ProxyLauncher::browser_quit_time() const {
   return browser_quit_time_;
 }
 
 // NamedProxyLauncher functions
 
 NamedProxyLauncher::NamedProxyLauncher(const std::string& channel_id,
-                                       bool launch_browser,
-                                       bool disconnect_on_failure)
+                                       const InitParams& params)
     : channel_id_(channel_id),
-      launch_browser_(launch_browser),
-      disconnect_on_failure_(disconnect_on_failure) {
+      launch_browser_(params.launch_browser),
+      disconnect_on_failure_(params.disconnect_on_failure),
+      wait_for_server_channel_(params.wait_for_server_channel) {
 }
 
 AutomationProxy* NamedProxyLauncher::CreateAutomationProxy(
     int execution_timeout) {
   AutomationProxy* proxy = new AutomationProxy(execution_timeout,
                                                disconnect_on_failure_);
   proxy->InitializeChannel(channel_id_, true);
   return proxy;
 }
 
-void NamedProxyLauncher::InitializeConnection(const LaunchState& state,
+bool NamedProxyLauncher::InitializeConnection(const LaunchState& state,
                                               bool wait_for_initial_loads) {
   FilePath testing_channel_path;
 #if defined(OS_WIN)
   testing_channel_path = FilePath(ASCIIToWide(channel_id_));
 #else
   testing_channel_path = FilePath(channel_id_);
 #endif
 
   if (launch_browser_) {
     // Because we are waiting on the existence of the testing file below,
     // make sure there isn't one already there before browser launch.
-    EXPECT_TRUE(file_util::Delete(testing_channel_path, false));
+    if (!file_util::Delete(testing_channel_path, false)) {
+      LOG(ERROR) << "Failed to delete " << testing_channel_path.value();
+      return false;
+    }
 
-    // Set up IPC testing interface as a client.
-    ASSERT_TRUE(LaunchBrowser(state));
+    if (!LaunchBrowser(state)) {
+      LOG(ERROR) << "Failed to LaunchBrowser";
+      return false;
+    }
   }
 
-  // Wait for browser to be ready for connections.
-  bool testing_channel_exists = false;
-  for (int wait_time = 0;
-       wait_time < TestTimeouts::action_max_timeout_ms();
-       wait_time += automation::kSleepTime) {
-    testing_channel_exists = file_util::PathExists(testing_channel_path);
-    if (testing_channel_exists)
-      break;
-    base::PlatformThread::Sleep(automation::kSleepTime);
+  if (wait_for_server_channel_) {
+    // Wait for browser to be ready for connections.
+    bool testing_channel_exists = false;
+    for (int wait_time = 0;
+         wait_time < TestTimeouts::action_max_timeout_ms();
+         wait_time += automation::kSleepTime) {
+      testing_channel_exists = file_util::PathExists(testing_channel_path);
+      if (testing_channel_exists)
+        break;
+      base::PlatformThread::Sleep(automation::kSleepTime);
+    }
+    if (!testing_channel_exists) {
+      LOG(ERROR) << "Failed to wait for testing channel presence.";
+      return false;
+    }
   }
-  EXPECT_TRUE(testing_channel_exists);
 
-  ASSERT_TRUE(ConnectToRunningBrowser(wait_for_initial_loads));
+  if (!ConnectToRunningBrowser(wait_for_initial_loads)) {
+    LOG(ERROR) << "Failed to ConnectToRunningBrowser";
+    return false;
+  }
+
+  return true;
 }
 
 void NamedProxyLauncher::TerminateConnection() {
   if (launch_browser_)
     CloseBrowserAndServer();
   else
     DisconnectFromRunningBrowser();
 }
 
 std::string NamedProxyLauncher::PrefixedChannelID() const {
@@ skipping 10 matching lines @@
 }
 
 AutomationProxy* AnonymousProxyLauncher::CreateAutomationProxy(
     int execution_timeout) {
   AutomationProxy* proxy = new AutomationProxy(execution_timeout,
                                                disconnect_on_failure_);
   proxy->InitializeChannel(channel_id_, false);
   return proxy;
 }
 
-void AnonymousProxyLauncher::InitializeConnection(const LaunchState& state,
+bool AnonymousProxyLauncher::InitializeConnection(const LaunchState& state,
                                                   bool wait_for_initial_loads) {
-  ASSERT_TRUE(LaunchBrowserAndServer(state, wait_for_initial_loads));
+  return LaunchBrowserAndServer(state, wait_for_initial_loads);
 }
 
 void AnonymousProxyLauncher::TerminateConnection() {
   CloseBrowserAndServer();
 }
 
 std::string AnonymousProxyLauncher::PrefixedChannelID() const {
   return channel_id_;
 }