wayland-protocols: Add protocol for explicit synchronization support.

third_party/wayland-protocols/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 config("xdg_shell_protocol_config") {
   include_dirs = [ "include/protocol" ]
 }
 
 source_set("xdg_shell_protocol") {
   sources = [
@@ skipping 172 matching lines @@
 
   deps = [
     "//third_party/wayland:wayland_util",
   ]
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
 
   public_configs = [ ":stylus_protocol_config" ]
 }
+
+config("linux_explicit_synchronization_protocol_config") {
+  include_dirs = [ "include/protocol" ]
+}
+
+source_set("linux_explicit_synchronization_protocol") {
+  sources = [
+    "include/protocol/linux-explicit-synchronization-unstable-v1-client-protocol.h",
+    "include/protocol/linux-explicit-synchronization-unstable-v1-server-protocol.h",
+    "protocol/linux-explicit-synchronization-protocol.c",
+  ]
+
+  deps = [
+    "//third_party/wayland:wayland_util",
+  ]
+
+  configs -= [ "//build/config/compiler:chromium_code" ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+
+  public_configs = [ ":linux_explicit_synchronization_protocol_config" ]
+}