Remove the helper dart script from our browser test framework
Remove the helper dart script from our browser test framework

BUG=https://github.com/dart-lang/sdk/issues/32539

Change-Id: Ia1d5c04babf21e244c807f32a21b43198a7151a5
Reviewed-on: https://dart-review.googlesource.com/60845
Reviewed-by: Jonas Termansen <092ec58085ae5e368bc39d18752740ff81a2d09c@google.com>

dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk