[Extensions] Don't allow content scripts on the New Tab Page

chrome/renderer/extensions/renderer_permissions_policy_delegate.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 "chrome/renderer/extensions/renderer_permissions_policy_delegate.h"
 
 #include "chrome/common/extensions/extension_constants.h"
+#include "chrome/renderer/searchbox/search_bouncer.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extensions_client.h"
 #include "extensions/common/manifest_constants.h"
 #include "extensions/common/switches.h"
 #include "extensions/renderer/dispatcher.h"
 
 namespace extensions {
 
 namespace errors = manifest_errors;
 
@@ skipping 12 matching lines @@
     std::string* error) {
   if (PermissionsData::CanExecuteScriptEverywhere(extension))
     return true;
 
   if (dispatcher_->IsExtensionActive(kWebStoreAppId)) {
     if (error)
       *error = errors::kCannotScriptGallery;
     return false;
   }
 
+  if (SearchBouncer::GetInstance()->IsNewTabPage(document_url)) {
+    if (error)
+      *error = errors::kCannotScriptNtp;
+    return false;
+  }
+
   return true;
 }
 
 }  // namespace extensions