mojo-ts: Add constants to generated TS bindings

Adds support for simple constants.

Example generated JS:

var mojo;
(function (mojo) {
    var tstest;
    (function (tstest) {
        tstest.kBoolValue = true;
        tstest.kInt8Value = -2;
    })(tstest = mojo.tstest || (mojo.tstest = {}));
})(mojo || (mojo = {})); // namespace mojo.tstest



Bug: 1002798
Change-Id: I31e15f204c541e563fcb5303657c3f6507bcdc19
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1827273
Reviewed-by: Ken Rockot <[email protected]>
Reviewed-by: Scott Violet <[email protected]>
Commit-Queue: Giovanni Ortuño Urquidi <[email protected]>
Cr-Commit-Position: refs/heads/master@{#702349}
diff --git a/BUILD.gn b/BUILD.gn
index 3ef251b4..0a5bcd64 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -1047,6 +1047,7 @@
       "//media/midi:mojo_js_data_deps",
       "//mojo/public/interfaces/bindings/tests:test_data_deps",
       "//mojo/public/mojom/base:base_js_data_deps",
+      "//mojo/public/js/ts/bindings/tests:test_interfaces_js_data_deps",
       "//services/shape_detection/public/mojom:mojom_js_data_deps",
       "//services/device/public/mojom:mojom_js_data_deps",
       "//services/device/public/mojom:generic_sensor_js_data_deps",