Revert of Remove the use of page id from NavController's GetVisibleEntry.

content/browser/frame_host/navigation_controller_impl.cc

 // Copyright 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 "content/browser/frame_host/navigation_controller_impl.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
@@ skipping 428 matching lines @@
   // initiated navigations.  Most renderer-initiated navigations should not
   // show the pending entry, to prevent URL spoof attacks.
   //
   // We make an exception for renderer-initiated navigations in new tabs, as
   // long as no other page has tried to access the initial empty document in
   // the new tab.  If another page modifies this blank page, a URL spoof is
   // possible, so we must stop showing the pending entry.
   bool safe_to_show_pending =
       pending_entry_ &&
       // Require a new navigation.
-      pending_entry_index_ == -1 &&
+      pending_entry_->GetPageID() == -1 &&
       // Require either browser-initiated or an unmodified new tab.
       (!pending_entry_->is_renderer_initiated() || IsUnmodifiedBlankTab());
 
   // Also allow showing the pending entry for history navigations in a new tab,
   // such as Ctrl+Back.  In this case, no existing page is visible and no one
   // can script the new tab before it commits.
   if (!safe_to_show_pending &&
       pending_entry_ &&
-      pending_entry_index_ != -1 &&
+      pending_entry_->GetPageID() != -1 &&
       IsInitialNavigation() &&
       !pending_entry_->is_renderer_initiated())
     safe_to_show_pending = true;
 
   if (safe_to_show_pending)
     return pending_entry_;
   return GetLastCommittedEntry();
 }
 
 int NavigationControllerImpl::GetCurrentEntryIndex() const {
@@ skipping 1308 matching lines @@
     }
   }
 }
 
 void NavigationControllerImpl::SetGetTimestampCallbackForTest(
     const base::Callback<base::Time()>& get_timestamp_callback) {
   get_timestamp_callback_ = get_timestamp_callback;
 }
 
 }  // namespace content