Install CRX updates one at a time.

chrome/browser/extensions/test_extension_service.cc

 // Copyright (c) 2011 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/extensions/crx_installer.h"
 #include "chrome/browser/extensions/extension_sync_data.h"
 #include "chrome/browser/extensions/test_extension_service.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TestExtensionService::~TestExtensionService() {}
 
 const ExtensionList* TestExtensionService::extensions() const {
   ADD_FAILURE();
   return NULL;
 }
 
 PendingExtensionManager* TestExtensionService::pending_extension_manager() {
   ADD_FAILURE();
   return NULL;
 }
 
-void TestExtensionService::UpdateExtension(const std::string& id,
-                                           const FilePath& path,
-                                           const GURL& download_url) {
+bool TestExtensionService::UpdateExtension(
+    const std::string& id,
+    const FilePath& path,
+    const GURL& download_url,
+    CrxInstaller** out_crx_installer) {
   ADD_FAILURE();
+  return NULL;
 }
 
 const Extension* TestExtensionService::GetExtensionById(
     const std::string& id, bool include_disabled) const {
   ADD_FAILURE();
   return NULL;
 }
 
 const Extension* TestExtensionService::GetInstalledExtension(
     const std::string& id) const {
@@ skipping 37 matching lines @@
     ExtensionFilter filter) const {
   ADD_FAILURE();
   return std::vector<ExtensionSyncData>();
 }
 
 void TestExtensionService::ProcessSyncData(
     const ExtensionSyncData& extension_sync_data,
     ExtensionFilter filter) {
   ADD_FAILURE();
 }