[Sync] Move sync/{internal_api,syncable} into syncer namespace

sync/test/engine/syncer_command_test.cc

Index: sync/test/engine/syncer_command_test.cc
diff --git a/sync/test/engine/syncer_command_test.cc b/sync/test/engine/syncer_command_test.cc
index 0d215c2de8e8923a4e34759e0ae4cf8004beb5fc..2439c1ba2c305744d42c1bf3a58bbab89e77e8a6 100644
--- a/sync/test/engine/syncer_command_test.cc
+++ b/sync/test/engine/syncer_command_test.cc
@@ -26,7 +26,7 @@ void SyncerCommandTestBase::SetUp() {
 void SyncerCommandTestBase::TearDown() {
 }
 
-Directory* SyncerCommandTest::directory() {
+syncable::Directory* SyncerCommandTest::directory() {
   return dir_maker_.directory();
 }
 
@@ -59,7 +59,7 @@ void MockDirectorySyncerCommandTest::SetUp() {
   ResetContext();
 }
 
-Directory* MockDirectorySyncerCommandTest::directory() {
+syncable::Directory* MockDirectorySyncerCommandTest::directory() {
   return &mock_directory_;
 }