where is weston-content-protection-client-protocol.h?

[Barry Song]

Hi Ankit and all,
clients/content_protection.c includes
weston-content-protection-client-protocol.h, and i found commit
8b40deaaaaf845c1b965c2888b1f036ef1f19d76 added
weston_content_protection_protocol_c and
weston_content_protection_client_protocol_h

diff --git a/clients/meson.build b/clients/meson.build
index 3d36efe4..ff6246db 100644
--- a/clients/meson.build
+++ b/clients/meson.build
@@ -229,6 +229,14 @@ demo_clients = [
                'dep_objs': dep_vertex_clipping
        },
        { 'basename': 'confine' },
+       {
+               'basename': 'content_protection',
+               'add_sources': [
+                       weston_content_protection_client_protocol_h,
+                       weston_content_protection_protocol_c,
+               ]
+       },
+
        { 'basename': 'dnd' },
        {
                'basename': 'editor',

But anyway, where is the weston-content-protection-client-protocol.h?
I can't find it in weston:
weston$ find ./ -name "weston-content-protection-client-protocol.h"

And i failed to find it in google.

Thanks
Barry