Fixes bug in handling of openning background tabs by way of clicking

chrome/browser/ui/browser.cc

 // Copyright (c) 2010 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 <shellapi.h>
 #include <windows.h>
 #endif  // OS_WIN
@@ skipping 4144 matching lines @@
     const TabContents* base_tab_contents,
     SessionStorageNamespace* session_storage_namespace) {
   TabContents* new_contents = new TabContents(profile, site_instance,
                                               routing_id, base_tab_contents,
                                               session_storage_namespace);
   TabContentsWrapper* wrapper = new TabContentsWrapper(new_contents);
   return wrapper;
 }
 
 bool Browser::OpenInstant(WindowOpenDisposition disposition) {
-  if (!instant() || !instant()->is_active() || !instant()->IsCurrent())
+  if (!instant() || !instant()->is_active() || !instant()->IsCurrent() ||
+      disposition == NEW_BACKGROUND_TAB) {
+    // NEW_BACKGROUND_TAB results in leaving the omnibox open, so we don't
+    // attempt to use the instant preview.
     return false;
+  }
 
   if (disposition == CURRENT_TAB) {
     instant()->CommitCurrentPreview(INSTANT_COMMIT_PRESSED_ENTER);
     return true;
   }
-  if (disposition == NEW_FOREGROUND_TAB || disposition == NEW_BACKGROUND_TAB) {
+  if (disposition == NEW_FOREGROUND_TAB) {
     TabContentsWrapper* preview_contents = instant()->ReleasePreviewContents(
         INSTANT_COMMIT_PRESSED_ENTER);
     // HideInstant is invoked after release so that InstantController is not
     // active when HideInstant asks it for its state.
     HideInstant();
     preview_contents->controller().PruneAllButActive();
     tab_handler_->GetTabStripModel()->AddTabContents(
         preview_contents,
         -1,
         instant()->last_transition_type(),
@@ skipping 67 matching lines @@
     // The page transition below is only for the purpose of inserting the tab.
     browser->AddTab(view_source_contents, PageTransition::LINK);
   }
 
   if (profile_->HasSessionService()) {
     SessionService* session_service = profile_->GetSessionService();
     if (session_service)
       session_service->TabRestored(&view_source_contents->controller(), false);
   }
 }