Port chromevox build to GN.

chrome/browser/resources/chromeos/braille_ime/BUILD.gn

Index: chrome/browser/resources/chromeos/braille_ime/BUILD.gn
diff --git a/mojo/util/BUILD.gn b/chrome/browser/resources/chromeos/braille_ime/BUILD.gn
similarity index 55%
copy from mojo/util/BUILD.gn
copy to chrome/browser/resources/chromeos/braille_ime/BUILD.gn
index 379bc96230e7c6037bca99a4a311de60a65c109a..092cbce3bc1a7d61cb869c4cb6f49362ef09dd05 100644
--- a/mojo/util/BUILD.gn
+++ b/chrome/browser/resources/chromeos/braille_ime/BUILD.gn
@@ -2,14 +2,13 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("filename_util") {
+assert(is_chromeos)
+
+copy("braille_ime_manifest") {
   sources = [
-    "filename_util.cc",
-    "filename_util.h",
+    "manifest.json",
   ]
-
-  deps = [
-    "//base",
-    "//url",
+  outputs = [
+    "$root_out_dir/resources/chromeos/braille_ime/manifest.json",
   ]
 }