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

sync/internal_api/public/write_node.h

Index: sync/internal_api/public/write_node.h
diff --git a/sync/internal_api/public/write_node.h b/sync/internal_api/public/write_node.h
index b1131871687fdc6008193af5ade6209f9c1b367b..d97c5867a65e7cd7b9d785f1cec789241e875162 100644
--- a/sync/internal_api/public/write_node.h
+++ b/sync/internal_api/public/write_node.h
@@ -14,16 +14,6 @@
 #include "sync/internal_api/public/base_node.h"
 #include "sync/internal_api/public/syncable/model_type.h"
 
-namespace syncer {
-class Cryptographer;
-class TestBookmarkModelAssociator;
-}
-
-namespace syncable {
-class Entry;
-class MutableEntry;
-}
-
 namespace sync_pb {
 class AppSpecifics;
 class AutofillSpecifics;
@@ -40,8 +30,15 @@ class TypedUrlSpecifics;
 
 namespace syncer {
 
+class Cryptographer;
+class TestBookmarkModelAssociator;
 class WriteTransaction;
 
+namespace syncable {
+class Entry;
+class MutableEntry;
+}
+
 // WriteNode extends BaseNode to add mutation, and wraps
 // syncable::MutableEntry. A WriteTransaction is needed to create a WriteNode.
 class WriteNode : public BaseNode {