[Chromedriver] Chromedriver should handle unexpected alert automatically.

chrome/test/chromedriver/window_commands.cc

 // Copyright (c) 2013 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/chromedriver/window_commands.h"
 
 #include <stddef.h>
 
 #include <list>
 #include <string>
@@ skipping 200 matching lines @@
     return status;
 
   status = web_view->ConnectIfNecessary();
   if (status.IsError())
     return status;
 
   status = web_view->HandleReceivedEvents();
   if (status.IsError())
     return status;
 
-  if (web_view->GetJavaScriptDialogManager()->IsDialogOpen()) {
+  JavaScriptDialogManager* dialog_manager =
+      web_view->GetJavaScriptDialogManager();
+  if (dialog_manager->IsDialogOpen()) {
     std::string alert_text;
-    status =
-        web_view->GetJavaScriptDialogManager()->GetDialogMessage(&alert_text);
+    status = dialog_manager->GetDialogMessage(&alert_text);
     if (status.IsError())
       return status;
+
+    // Close the dialog depending on the unexpectedalert behaviour set by user
+    // before returning an error, so that subsequent commands do not fail.
+    std::string alert_behaviour = session->unexpected_alert_behaviour;
+    if (alert_behaviour == kAccept)
+      status = dialog_manager->HandleDialog(true, session->prompt_text.get());
+    else if (alert_behaviour == kDismiss)
+      status = dialog_manager->HandleDialog(false, session->prompt_text.get());
+    if (status.IsError())
+      return status;
+
     return Status(kUnexpectedAlertOpen, "{Alert text : " + alert_text + "}");
   }
 
   Status nav_status(kOk);
   for (int attempt = 0; attempt < 3; attempt++) {
     if (attempt == 2) {
       // Switch to main frame and retry command if subframe no longer exists.
       session->SwitchToTopFrame();
     }
 
@@ skipping 827 matching lines @@
   return status;
 }
 
 Status ExecuteTakeHeapSnapshot(Session* session,
                                WebView* web_view,
                                const base::DictionaryValue& params,
                                std::unique_ptr<base::Value>* value,
                                Timeout* timeout) {
   return web_view->TakeHeapSnapshot(value);
 }