Add dep on dart_snapshotter_bin label in dartx rule
This requires that //build/module_args/dart.gni provide a label for
dart_snapshotter_bin and adds a dep in the dartx rule on the target. A
future patch will add a way to download a prebuilt binary.
R=zra@google.com, zra
Review URL: https://codereview.chromium.org/1294023004 .
diff --git a/build/module_args/dart.gni b/build/module_args/dart.gni
index ee6b038..e784261 100644
--- a/build/module_args/dart.gni
+++ b/build/module_args/dart.gni
@@ -4,3 +4,5 @@
# This variable should point to the Dart SDK.
dart_sdk_root = "//third_party/dart-sdk/dart-sdk"
+
+dart_snapshotter_bin = "//mojo/dart/dart_snapshotter($host_toolchain)"
