[Sync] Rename csync namespace to syncer

sync/api/sync_change.h

Index: sync/api/sync_change.h
diff --git a/sync/api/sync_change.h b/sync/api/sync_change.h
index 11dea71c6409df3226dbb1941d98f4a575349b64..63a03d9606c3496d107ae22c907a4ae7d1b2b5c0 100644
--- a/sync/api/sync_change.h
+++ b/sync/api/sync_change.h
@@ -12,7 +12,7 @@
 
 #include "sync/api/sync_data.h"
 
-namespace csync {
+namespace syncer {
 
 // A SyncChange object reflects a change to a piece of synced data. The change
 // can be either a delete, add, or an update. All data relevant to the change
@@ -66,6 +66,6 @@ class SyncChange {
 // gmock printer helper.
 void PrintTo(const SyncChange& sync_change, std::ostream* os);
 
-}  // namespace csync
+}  // namespace syncer
 
 #endif  // SYNC_API_SYNC_CHANGE_H_