Rename "libchromeos" into "libbrillo"

Renamed libchromeos[-.*] libraries into libbrillo-...

BUG: 24872993
Change-Id: Ibab1623b6a08a55cae3662e941d0d6644ff14df4
diff --git a/brillo/osrelease_reader.h b/brillo/osrelease_reader.h
index b72f733..f29c14d 100644
--- a/brillo/osrelease_reader.h
+++ b/brillo/osrelease_reader.h
@@ -6,8 +6,8 @@
 // Standard fields can come from both places depending on how we set them. They
 // should always be accessed through this interface.
 
-#ifndef LIBCHROMEOS_BRILLO_OSRELEASE_READER_H_
-#define LIBCHROMEOS_BRILLO_OSRELEASE_READER_H_
+#ifndef LIBBRILLO_BRILLO_OSRELEASE_READER_H_
+#define LIBBRILLO_BRILLO_OSRELEASE_READER_H_
 
 #include <string>
 
@@ -51,4 +51,4 @@
 
 }  // namespace brillo
 
-#endif  // LIBCHROMEOS_BRILLO_OSRELEASE_READER_H_
+#endif  // LIBBRILLO_BRILLO_OSRELEASE_READER_H_