🐼 Regenerate .device.isolate when .runtime_deps changes.

testing/test.gni

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # ==============================================================================
 # TEST SETUP
 # ==============================================================================
 
 template("_gen_isolate") {
   testonly = true
   _runtime_deps_file = "$target_gen_dir/$target_name.runtime_deps"
   group("${target_name}__write_deps") {
     forward_variables_from(invoker,
                            [
                              "data",
                              "data_deps",
                              "deps",
                              "public_deps",
                            ])
     write_runtime_deps = _runtime_deps_file
   }
 
   action(target_name) {
     script = "//testing/generate_isolate.py"
+    inputs = [
+      _runtime_deps_file,
+    ]
     outputs = [
       invoker.output,
     ]
     args = [
       "--output-directory=.",
       "--out-file",
       rebase_path(invoker.output, root_build_dir),
       "--runtime-deps-file",
       rebase_path(_runtime_deps_file, root_build_dir),
     ]
@@ skipping 302 matching lines @@
     # TODO(GYP): Delete this after we've converted everything to GN.
     # The _run targets exist only for compatibility with GYP.
     group("${target_name}_run") {
       testonly = true
       deps = [
         ":${invoker.target_name}",
       ]
     }
   }
 }