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

chrome/test/webdriver/commands/create_session.cc

Index: chrome/test/webdriver/commands/create_session.cc
diff --git a/chrome/test/webdriver/commands/create_session.cc b/chrome/test/webdriver/commands/create_session.cc
index efb8ff968d469f0d48e9de99c89ac0d6f49e5029..525bfec56a75d856f19992ca8674abf557f18532 100644
--- a/chrome/test/webdriver/commands/create_session.cc
+++ b/chrome/test/webdriver/commands/create_session.cc
@@ -42,7 +42,11 @@ void CreateSession::ExecutePost(Response* const response) {
     return;
   }
 
-  CommandLine command_line_options(CommandLine::NO_PROGRAM);
+  Automation::InitOptions options;
+  FilePath::StringType path;
+  if (capabilities->GetStringWithoutPathExpansion("chrome.binary", &path))
+    options.cmdline = CommandLine(FilePath(path));
+
   ListValue* switches = NULL;
   const char* kCustomSwitchesKey = "chrome.switches";
   if (capabilities->GetListWithoutPathExpansion(kCustomSwitchesKey,
@@ -62,11 +66,11 @@ void CreateSession::ExecutePost(Response* const response) {
               kBadRequest, "Custom switch is not a string"));
           return;
         }
-        command_line_options.AppendSwitchNative(
+        options.cmdline.AppendSwitchNative(
             switch_string.substr(0, separator_index),
             switch_string_native.substr(separator_index + 1));
       } else {
-        command_line_options.AppendSwitch(switch_string);
+        options.cmdline.AppendSwitch(switch_string);
       }
     }
   } else if (capabilities->HasKey(kCustomSwitchesKey)) {
@@ -74,14 +78,16 @@ void CreateSession::ExecutePost(Response* const response) {
         kBadRequest, "Custom switches must be a list"));
     return;
   }
+
   Value* verbose_value;
   if (capabilities->GetWithoutPathExpansion("chrome.verbose", &verbose_value)) {
-    bool verbose;
-    if (verbose_value->GetAsBoolean(&verbose) && verbose) {
+    bool verbose = false;
+    if (verbose_value->GetAsBoolean(&verbose)) {
       // Since logging is shared among sessions, if any session requests verbose
       // logging, verbose logging will be enabled for all sessions. It is not
       // possible to turn it off.
-      logging::SetMinLogLevel(logging::LOG_INFO);
+      if (verbose)
+        logging::SetMinLogLevel(logging::LOG_INFO);
     } else {
       response->SetError(new Error(
           kBadRequest, "verbose must be a boolean true or false"));
@@ -89,10 +95,8 @@ void CreateSession::ExecutePost(Response* const response) {
     }
   }
 
-  FilePath browser_exe;
-  FilePath::StringType path;
-  if (capabilities->GetStringWithoutPathExpansion("chrome.binary", &path))
-    browser_exe = FilePath(path);
+  capabilities->GetStringWithoutPathExpansion(
+      "chrome.channel", &options.channel_id);
 
   ScopedTempDir temp_dir;
   FilePath temp_user_data_dir;
@@ -130,9 +134,7 @@ void CreateSession::ExecutePost(Response* const response) {
 
   // Session manages its own liftime, so do not call delete.
   Session* session = new Session();
-  Error* error = session->Init(browser_exe,
-                               temp_user_data_dir,
-                               command_line_options);
+  Error* error = session->Init(options);
   if (error) {
     response->SetError(error);
     return;