[chromedriver] Implement reconnection to DevTools.

chrome/test/chromedriver/commands.cc

 // Copyright (c) 2012 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/commands.h"
 
 #include "base/callback.h"
 #include "base/environment.h"
 #include "base/file_util.h"
 #include "base/string_split.h"
@@ skipping 119 matching lines @@
     return Status(kSessionNotCreatedException, status.message());
 
   std::list<WebView*> web_views;
   status = chrome->GetWebViews(&web_views);
   if (status.IsError() || web_views.empty()) {
     chrome->Quit();
     return status.IsError() ? status :
         Status(kUnknownError, "unable to discover open window in chrome");
   }
   WebView* default_web_view = web_views.front();
+  status = default_web_view->EnsureAlive();
+  if (status.IsError())
+    return status;
 
   std::string chrome_version;
   status = CheckChromeVersion(default_web_view, &chrome_version);
   if (status.IsError()) {
     chrome->Quit();
     return status;
   }
 
   std::string new_id = session_id;
   if (new_id.empty())
@@ skipping 22 matching lines @@
     std::string* out_session_id) {
   std::vector<std::string> session_ids;
   session_map->GetKeys(&session_ids);
   for (size_t i = 0; i < session_ids.size(); ++i) {
     scoped_ptr<base::Value> unused_value;
     std::string unused_session_id;
     quit_command.Run(params, session_ids[i], &unused_value, &unused_session_id);
   }
   return Status(kOk);
 }