fix to show detached bookmark bar on NTP when "Show bookmarks bar" is on.

chrome/browser/ui/browser.cc

 // Copyright 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/browser/ui/browser.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #include <shellapi.h>
 #endif  // defined(OS_WIN)
@@ skipping 1030 matching lines @@
   if (instant_controller_)
     instant_controller_->TabDeactivated(contents);
 }
 
 void Browser::ActiveTabChanged(WebContents* old_contents,
                                WebContents* new_contents,
                                int index,
                                int reason) {
   content::RecordAction(UserMetricsAction("ActiveTabChanged"));
 
-  // First let the BrowserWindow do its handling.  On e.g. views this changes
-  // the focused object, which should happen before we update the toolbar below,
+  // First, determine the new bookmark state, so that it can be queried by
+  // BrowserWindow::BookmarkBarStateChanged() when it's invoked from
+  // BrowserWindow::OnActiveTabChanged() below.
+  // Note that UpdateBookmarkBarState() won't invoke
+  // BrowserWindow::BookmarkBarStateChanged() for
+  // BOOKMARK_BAR_STATE_CHANGE_TAB_SWITCH reason.

[Peter Kasting, 2013/10/01 20:44:11]

Nit: Can we just say:

Update the bookmark bar state, since the BrowserWindow may query it during
OnActiveTabChanged() below.

[kuan, 2013/10/02 00:15:37]

Done.

+  UpdateBookmarkBarState(BOOKMARK_BAR_STATE_CHANGE_TAB_SWITCH);
+
+  // Let the BrowserWindow do its handling.  On e.g. views this changes the
+  // focused object, which should happen before we update the toolbar below,
   // since the omnibox expects the correct element to already be focused when it
   // is updated.
   window_->OnActiveTabChanged(old_contents, new_contents, index, reason);
 
   // Discarded tabs always get reloaded.
   if (tab_strip_model_->IsTabDiscarded(index)) {
     LOG(WARNING) << "Reloading discarded tab at " << index;
     static int reload_count = 0;
     UMA_HISTOGRAM_CUSTOM_COUNTS(
         "Tabs.Discard.ReloadCount", ++reload_count, 1, 1000, 50);
@@ skipping 33 matching lines @@
 
   // Update sessions. Don't force creation of sessions. If sessions doesn't
   // exist, the change will be picked up by sessions when created.
   SessionService* session_service =
       SessionServiceFactory::GetForProfileIfExisting(profile_);
   if (session_service && !tab_strip_model_->closing_all()) {
     session_service->SetSelectedTabInWindow(session_id(),
                                             tab_strip_model_->active_index());
   }
 
-  UpdateBookmarkBarState(BOOKMARK_BAR_STATE_CHANGE_TAB_SWITCH);
-
   // This needs to be called after UpdateSearchState().
   if (instant_controller_)
     instant_controller_->ActiveTabChanged();
 
   autofill::TabAutofillManagerDelegate::FromWebContents(new_contents)->
       TabActivated(reason);
 }
 
 void Browser::TabMoved(WebContents* contents,
                        int from_index,
@@ skipping 1175 matching lines @@
   if (contents && !allow_js_access) {
     contents->web_contents()->GetController().LoadURL(
         target_url,
         content::Referrer(),
         content::PAGE_TRANSITION_LINK,
         std::string());  // No extra headers.
   }
 
   return contents != NULL;
 }