Move dart_debugger into tonic and use it in mojo dart controller

mojo/dart/embedder/BUILD.gn

 # Copyright 2014 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.
 
 # embedder specific template rules.
 import("embedder.gni")
 
 source_set("dart_controller_no_snapshot") {
   sources = [
     "$target_gen_dir/dart_embedder_patch_resources.cc",
     "$target_gen_dir/dart_embedder_service_isolate_resources.cc",
     "builtin.cc",
     "builtin.h",
     "builtin_natives.cc",
     "common.cc",
     "common.h",
     "dart_controller.cc",
     "dart_controller.h",
-    "dart_debugger.cc",
-    "dart_debugger.h",
     "io/internet_address.h",
     "mojo_io_natives.cc",
     "mojo_io_natives.h",
     "mojo_natives.cc",
     "mojo_natives.h",
-    "monitor.h",
     "vmservice.cc",
     "vmservice.h",
   ]
 
   if (is_linux) {
     sources += [ "io/internet_address_linux.cc" ]
   }
 
   if (is_android) {
     sources += [ "io/internet_address_android.cc" ]
@@ skipping 367 matching lines @@
     "--vm_input_bin",
     rebase_path("$target_gen_dir/vm_isolate_snapshot.bin"),
     "--input_bin",
     rebase_path("$target_gen_dir/isolate_snapshot.bin"),
     "--input_cc",
     rebase_path("//mojo/dart/embedder/snapshot.cc.tmpl"),
     "--output",
     rebase_path(output),
   ]
 }