Introduce a layering in the invalidation component as public and impl

components/invalidation/impl/p2p_invalidator.cc

Index: components/invalidation/impl/p2p_invalidator.cc
diff --git a/components/invalidation/p2p_invalidator.cc b/components/invalidation/impl/p2p_invalidator.cc
similarity index 96%
rename from components/invalidation/p2p_invalidator.cc
rename to components/invalidation/impl/p2p_invalidator.cc
index aea1e3a4bdb5979702e36fcae225a65b85a2d9cc..4f39cbd29bcfb6420b05676d484a4f112159eb42 100644
--- a/components/invalidation/p2p_invalidator.cc
+++ b/components/invalidation/impl/p2p_invalidator.cc
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "components/invalidation/p2p_invalidator.h"
+#include "components/invalidation/impl/p2p_invalidator.h"
 
 #include <algorithm>
 #include <iterator>
@@ -11,10 +11,10 @@
 #include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "base/values.h"
-#include "components/invalidation/invalidation_handler.h"
-#include "components/invalidation/invalidation_util.h"
-#include "components/invalidation/notifier_reason_util.h"
-#include "components/invalidation/object_id_invalidation_map.h"
+#include "components/invalidation/impl/notifier_reason_util.h"
+#include "components/invalidation/public/invalidation_handler.h"
+#include "components/invalidation/public/invalidation_util.h"
+#include "components/invalidation/public/object_id_invalidation_map.h"
 #include "jingle/notifier/listener/push_client.h"
 
 namespace syncer {