[Sync] Move //components/sync to the syncer namespace.

components/sync/api/sync_change_processor.cc

Index: components/sync/api/sync_change_processor.cc
diff --git a/components/sync/api/sync_change_processor.cc b/components/sync/api/sync_change_processor.cc
index 3a0b6a05a3ddbf5d5d02d89e09584ffb1657a655..ba88478d8a3da83474fd77a9e1e2a539261f3d23 100644
--- a/components/sync/api/sync_change_processor.cc
+++ b/components/sync/api/sync_change_processor.cc
@@ -10,12 +10,12 @@ SyncChangeProcessor::SyncChangeProcessor() {}
 
 SyncChangeProcessor::~SyncChangeProcessor() {}
 
-syncer::SyncError SyncChangeProcessor::UpdateDataTypeContext(
+SyncError SyncChangeProcessor::UpdateDataTypeContext(
     ModelType type,
-    syncer::SyncChangeProcessor::ContextRefreshStatus refresh_status,
+    SyncChangeProcessor::ContextRefreshStatus refresh_status,
     const std::string& context) {
   // Do nothing.
-  return syncer::SyncError();
+  return SyncError();
 }
 
 void SyncChangeProcessor::AddLocalChangeObserver(