[ChromeDriver] Select the main frame if a non-existant child frame is targeted.

chrome/test/chromedriver/session.h

 // 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.
 
 #ifndef CHROME_TEST_CHROMEDRIVER_SESSION_H_
 #define CHROME_TEST_CHROMEDRIVER_SESSION_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/lock.h"
 #include "chrome/test/chromedriver/basic_types.h"
 
 class Chrome;
+class Status;
 
 struct Session {
   explicit Session(const std::string& id);
   Session(const std::string& id, scoped_ptr<Chrome> chrome);
   ~Session();
+  Status WaitForPendingNavigations();
 
   const std::string id;
   scoped_ptr<Chrome> chrome;
   std::string frame;
   WebPoint mouse_position;
   int implicit_wait;
   int page_load_timeout;
   int script_timeout;
 };
 
@@ skipping 15 matching lines @@
  private:
   virtual ~SessionAccessorImpl();
 
   base::Lock session_lock_;
   scoped_ptr<Session> session_;
 
   DISALLOW_COPY_AND_ASSIGN(SessionAccessorImpl);
 };
 
 #endif  // CHROME_TEST_CHROMEDRIVER_SESSION_H_