[chromedriver] Add chrome.detach option for configuring Chrome not to quit

chrome/test/webdriver/commands/webdriver_command.cc

Index: chrome/test/webdriver/commands/webdriver_command.cc
diff --git a/chrome/test/webdriver/commands/webdriver_command.cc b/chrome/test/webdriver/commands/webdriver_command.cc
index 3220316985ed8488ebddb9058e6bddd03b8e54a4..c72d1d59160773f3ce67cd1a9747019a1e2195bf 100644
--- a/chrome/test/webdriver/commands/webdriver_command.cc
+++ b/chrome/test/webdriver/commands/webdriver_command.cc
@@ -50,4 +50,12 @@ bool WebDriverCommand::Init(Response* const response) {
   return true;
 }
 
+void WebDriverCommand::Finish() {
+  scoped_ptr<Error> error(session_->AfterExecuteCommand());
+  if (error.get()) {
+    LOG(WARNING) << "Command did not finish successfully: "
+                 << error->GetMessage();
+  }
+}
+
 }  // namespace webdriver