Introduce a layering in the invalidation component as public and impl

components/invalidation/invalidator_registrar.h

Index: components/invalidation/invalidator_registrar.h
diff --git a/components/invalidation/invalidator_registrar.h b/components/invalidation/invalidator_registrar.h
index 9acf26c0a0b779f56bbbe90fe92594323f6087f5..d96383b01c5e0d278aa95b0169912a3a801786cf 100644
--- a/components/invalidation/invalidator_registrar.h
+++ b/components/invalidation/invalidator_registrar.h
@@ -10,9 +10,9 @@
 #include "base/basictypes.h"
 #include "base/observer_list.h"
 #include "base/threading/thread_checker.h"
-#include "components/invalidation/invalidation_export.h"
-#include "components/invalidation/invalidation_handler.h"
-#include "components/invalidation/invalidation_util.h"
+#include "components/invalidation/base/invalidation_export.h"
+#include "components/invalidation/base/invalidation_handler.h"
+#include "components/invalidation/base/invalidation_util.h"
 
 namespace invalidation {
 class ObjectId;