Basic support for dev_compiler in test.dart.

tools/testing/dart/browser_controller.dart

Index: tools/testing/dart/browser_controller.dart
diff --git a/tools/testing/dart/browser_controller.dart b/tools/testing/dart/browser_controller.dart
index 50e14c15b7bfa889a97771d528b215edfa699f7d..3700a29aeb6814ea3252307f52b91ce5a7ff01f4 100644
--- a/tools/testing/dart/browser_controller.dart
+++ b/tools/testing/dart/browser_controller.dart
@@ -502,8 +502,13 @@ class Chrome extends Browser {
           "--disable-extensions",
           "--disable-popup-blocking",
           "--bwsi",
-          "--no-first-run"
+          "--no-first-run",
         ];
+
+        // TODO(rnystrom): Uncomment this to open the dev tools tab when Chrome

[Bill Hesse, 2017/06/21 16:33:20]

Commented code is disallowed, I think.  You could write it not as code, but as a
pure comment.

[Bob Nystrom, 2017/06/21 20:18:28]

Done.

+        // is spawned. Handy for debugging tests.
+        // args.add("--auto-open-devtools-for-tabs");
+
         return startBrowserProcess(_binary, args,
             environment: _getEnvironment());
       });