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

chrome/test/webdriver/commands/command.h

Index: chrome/test/webdriver/commands/command.h
diff --git a/chrome/test/webdriver/commands/command.h b/chrome/test/webdriver/commands/command.h
index 672b2c055424203824ec447ce6f623345c762129..8f735f833f40f005bc0b8adf246ca8bb75ae1c45 100644
--- a/chrome/test/webdriver/commands/command.h
+++ b/chrome/test/webdriver/commands/command.h
@@ -15,6 +15,7 @@
 
 namespace webdriver {
 
+class Error;
 class Response;
 
 // Base class for a command mapped to a URL in the WebDriver REST API. Each
@@ -37,6 +38,11 @@ class Command {
   // to return to the client.
   virtual bool Init(Response* const response);
 
+  // Called after this command is executed. Returns NULL if no error occurs.
+  // This is only called if |Init| is successful and regardless of whether
+  // the execution results in a |Error|.
+  virtual void Finish();
+
   // Executes the corresponding variant of this command URL.
   // Always called after |Init()| and called from the Execute function.
   // Any failure is handled as a return code found in Response.