sync: remove use of protobuf extensions in protocol to reduce static init overhead.

chrome/browser/extensions/app_notification_manager_sync_unittest.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 "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
 #include "base/string_number_conversions.h"
 #include "chrome/browser/extensions/app_notification.h"
 #include "chrome/browser/extensions/app_notification_manager.h"
 #include "chrome/browser/sync/protocol/app_notification_specifics.pb.h"
+#include "chrome/browser/sync/protocol/sync.pb.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/test/test_browser_thread.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using content::BrowserThread;
 
 namespace {
 
 // Extract notification guid from SyncData.
 std::string GetGuid(const SyncData& sync_data) {
-  return sync_data.GetSpecifics().GetExtension(
-      sync_pb::app_notification).guid();
+  return sync_data.GetSpecifics().app_notification().guid();
 }
 
 // Dummy SyncChangeProcessor used to help review what SyncChanges are pushed
 // back up to Sync.
 class TestChangeProcessor : public SyncChangeProcessor {
  public:
   TestChangeProcessor() { }
   virtual ~TestChangeProcessor() { }
 
   // Store a copy of all the changes passed in so we can examine them later.
@@ skipping 576 matching lines @@
 
   EXPECT_EQ(3, processor()->change_list_size());
   EXPECT_TRUE(processor()->ContainsGuid(n1->guid()));
   SyncChange c1 = processor()->GetChangeByGuid(n1->guid());
   AssertSyncChange(c1, SyncChange::ACTION_DELETE, *n1);
   SyncChange c2 = processor()->GetChangeByGuid(n2->guid());
   AssertSyncChange(c2, SyncChange::ACTION_DELETE, *n2);
   SyncChange c3 = processor()->GetChangeByGuid(n3->guid());
   AssertSyncChange(c3, SyncChange::ACTION_DELETE, *n3);
 }