Implement an API to allow passing an "ap" parameter to component updates.

chrome/browser/component_updater/ev_whitelist_component_installer.cc

 // Copyright 2014 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/component_updater/ev_whitelist_component_installer.h"
 
 #include <string>
 #include <utility>
 #include <vector>
 
@@ skipping 114 matching lines @@
 void EVWhitelistComponentInstallerTraits::GetHash(
     std::vector<uint8_t>* hash) const {
   hash->assign(kPublicKeySHA256,
                kPublicKeySHA256 + arraysize(kPublicKeySHA256));
 }
 
 std::string EVWhitelistComponentInstallerTraits::GetName() const {
   return kEVWhitelistManifestName;
 }
 
+std::string EVWhitelistComponentInstallerTraits::GetAp() const {
+  return std::string();
+}
+
 void RegisterEVWhitelistComponent(ComponentUpdateService* cus,
                                   const base::FilePath& user_data_dir) {
   VLOG(1) << "Registering EV whitelist component.";
 
   scoped_ptr<ComponentInstallerTraits> traits(
       new EVWhitelistComponentInstallerTraits());
   // |cus| will take ownership of |installer| during installer->Register(cus).
   DefaultComponentInstaller* installer =
       new DefaultComponentInstaller(std::move(traits));
   installer->Register(cus, base::Closure());
 
   content::BrowserThread::PostAfterStartupTask(
       FROM_HERE, content::BrowserThread::GetBlockingPool(),
       base::Bind(&DeleteWhitelistCopy, user_data_dir));
 }
 
 }  // namespace component_updater