[Experiment] Transpile mojo public js.

mojo/public/js/BUILD.gn

Index: mojo/public/js/BUILD.gn
diff --git a/mojo/public/js/BUILD.gn b/mojo/public/js/BUILD.gn
index eda7e04d07ef67f2e819bcbfb6fa1da79803f8bc..a2e2fc3da50f7f95f4d06fd53ca76596967d7a8d 100644
--- a/mojo/public/js/BUILD.gn
+++ b/mojo/public/js/BUILD.gn
@@ -2,6 +2,8 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/util/java_action.gni")
+
 source_set("js") {
   sources = [
     "constants.cc",
@@ -27,6 +29,50 @@ group("bindings") {
   ]
 }
 
+template("js_binary") {
+  closure_compiler_path = "//third_party/closure_compiler/compiler/compiler.jar"
+  output_file_path = "$target_gen_dir/$target_name.js"
+
+  java_action(target_name) {
+    script = closure_compiler_path
+    sources = invoker.sources
+    outputs = [
+      "$output_file_path",
+    ]
+    args = [
+             "--compilation_level",
+             "WHITESPACE_ONLY",
+             "--dependency_mode",
+             "STRICT",
+             "--transform_amd_modules",
+             "--process_common_js_modules",
+             "--language_out",
+             "ECMASCRIPT5",
+             "--formatting",
+             "PRETTY_PRINT",
+             "--js_output_file",
+             rebase_path("$output_file_path", root_build_dir),
+             "--entry_point",
+             rebase_path("main.js", root_build_dir),
+             "--js",
+           ] + rebase_path(sources, root_build_dir)
+  }
+}
+
+js_binary("lib") {
+  sources = [
+    "bindings.js",
+    "buffer.js",
+    "codec.js",
+    "connection.js",
+    "connector.js",
+    "main.js",
+    "router.js",
+    "unicode.js",
+    "validator.js",
+  ]
+}
+
 group("tests") {
   testonly = true