sync: add a BackendMigrator class to perform migration flow.
The rest of the change (more innocent than it looks) is mostly callback plumbing to make the long trek from SyncerProtoUtil up to ProfileSyncService.
BUG=79247
TEST=BackendMigratorTest
Review URL: http://codereview.chromium.org/6858002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@82215 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 1487d625..b37bb37 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1973,6 +1973,8 @@
'browser/sync/glue/typed_url_model_associator.h',
'browser/sync/glue/ui_model_worker.cc',
'browser/sync/glue/ui_model_worker.h',
+ 'browser/sync/backend_migrator.cc',
+ 'browser/sync/backend_migrator.h',
'browser/sync/profile_sync_factory.h',
'browser/sync/profile_sync_factory_impl.cc',
'browser/sync/profile_sync_factory_impl.h',
