Move all core files in //components/sessions into core/ subdir

components/sessions/core/session_backend.h

Index: components/sessions/core/session_backend.h
diff --git a/components/sessions/session_backend.h b/components/sessions/core/session_backend.h
similarity index 93%
rename from components/sessions/session_backend.h
rename to components/sessions/core/session_backend.h
index 8679793ca6b54dc68db27d488b3f222ff95aa169..aee36662a434e1a9243da2ea64ec3eed2fd61a4c 100644
--- a/components/sessions/session_backend.h
+++ b/components/sessions/core/session_backend.h
@@ -2,17 +2,17 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef COMPONENTS_SESSIONS_SESSION_BACKEND_H_
-#define COMPONENTS_SESSIONS_SESSION_BACKEND_H_
+#ifndef COMPONENTS_SESSIONS_CORE_SESSION_BACKEND_H_
+#define COMPONENTS_SESSIONS_CORE_SESSION_BACKEND_H_
 
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/task/cancelable_task_tracker.h"
-#include "components/sessions/base_session_service.h"
-#include "components/sessions/session_command.h"
-#include "components/sessions/sessions_export.h"
+#include "components/sessions/core/base_session_service.h"
+#include "components/sessions/core/session_command.h"
+#include "components/sessions/core/sessions_export.h"
 
 namespace base {
 class File;
@@ -142,4 +142,4 @@ class SESSIONS_EXPORT SessionBackend
 
 }  // namespace sessions
 
-#endif  // COMPONENTS_SESSIONS_SESSION_BACKEND_H_
+#endif  // COMPONENTS_SESSIONS_CORE_SESSION_BACKEND_H_