Added Fullscreen Shell protocol configs to BUILD file

Modified third_party build file to include Fullscreen Shell protocol,
allowing use of the protocol for EXO eventually.

Bug: b/74068068
Test: Compiled ChromeOS and verified it builds.
Change-Id: If785b9736679be2e18be5521e173888ab6ea6a6f
Reviewed-on: https://chromium-review.googlesource.com/c/1281175Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Shawn Gallea <sagallea@google.com>
Cr-Commit-Position: refs/heads/master@{#600447}

third_party/wayland-protocols/BUILD.gn

@@ -385,3 +385,24 @@ source_set("notification_shell_protocol") {
 
   public_configs = [ ":notification_shell_protocol_config" ]
 }
+
+config("fullscreen_shell_protocol_config") {
+  include_dirs = [ "include/protocol" ]
+}
+
+source_set("fullscreen_shell_protocol") {
+  sources = [
+    "include/protocol/fullscreen-shell-unstable-v1-client-protocol.h",
+    "include/protocol/fullscreen-shell-unstable-v1-server-protocol.h",
+    "protocol/fullscreen-shell-v1-protocol.c",
+  ]
+
+  deps = [
+    "//third_party/wayland:wayland_util",
+  ]
+
+  configs -= [ "//build/config/compiler:chromium_code" ]
+  configs += [ "//build/config/compiler:no_chromium_code" ]
+
+  public_configs = [ ":fullscreen_shell_protocol_config" ]
+}