ui: accessibility: remove -Wunused-function for Atk

build/config/linux/BUILD.gn

Index: build/config/linux/BUILD.gn
diff --git a/build/config/linux/BUILD.gn b/build/config/linux/BUILD.gn
index 3d65937dd42dd6cee74f4e79c9a56ec77b978446..202fd731897a89f29addd715f1c1150b751dde3c 100644
--- a/build/config/linux/BUILD.gn
+++ b/build/config/linux/BUILD.gn
@@ -35,25 +35,6 @@ config("sdk") {
   }
 }
 
-pkg_config("atk") {
-  packages = [ "atk" ]
-  atk_lib_dir = exec_script(pkg_config_script,
-                            [
-                              "--libdir",
-                              "atk",
-                            ],
-                            "string")
-  defines = [ "ATK_LIB_DIR=\"$atk_lib_dir\"" ]
-}
-
-# gn orders flags on a target before flags from configs. The default config
-# adds -Wall, and these flags have to be after -Wall -- so they need to come
-# from a config and can't be on the target directly.
-config("atk_warnings") {
-  # glib uses the pre-c++11 typedef-as-static_assert hack.
-  cflags = [ "-Wno-unused-local-typedef" ]
-}
-
 config("fontconfig") {
   libs = [ "fontconfig" ]
 }