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

chrome/test/webdriver/webdriver_session.h

Index: chrome/test/webdriver/webdriver_session.h
diff --git a/chrome/test/webdriver/webdriver_session.h b/chrome/test/webdriver/webdriver_session.h
index 10e158cc76d48ef211bad9ed84e51e60ede82b2b..7c2f6b632f40ce7f24b8e50e214697e34775fca2 100644
--- a/chrome/test/webdriver/webdriver_session.h
+++ b/chrome/test/webdriver/webdriver_session.h
@@ -77,10 +77,12 @@ class Session {
   // itself and return an error code.
   Error* Init(const Automation::BrowserOptions& options);
 
-  // Should be called before executing a command. Performs necessary waits
-  // and frame switching.
+  // Should be called before executing a command.
   Error* BeforeExecuteCommand();
 
+  // Should be called after executing a command.
+  Error* AfterExecuteCommand();
+
   // Terminates this session and deletes itself.
   void Terminate();