Add 'dart:debugger' library

runtime/lib/debugger.cc

+// Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "vm/bootstrap_natives.h"
+
+#include "include/dart_api.h"
+
+#include "vm/debugger.h"
+#include "vm/exceptions.h"
+#include "vm/native_entry.h"
+#include "vm/object.h"
+#include "vm/object_store.h"
+
+namespace dart {
+
+// dart:debugger.
+
+DEFINE_NATIVE_ENTRY(Debugger_breakHere, 0) {
+  Debugger* debugger = isolate->debugger();
+  if (!debugger) {
+    return Object::null();
+  }
+  debugger->BreakHere();
+  return Object::null();
+}
+
+
+DEFINE_NATIVE_ENTRY(Debugger_breakHereIf, 1) {
+  Debugger* debugger = isolate->debugger();
+  if (!debugger) {
+    return Object::null();
+  }
+  GET_NON_NULL_NATIVE_ARGUMENT(Bool, expr, arguments->NativeArgAt(0));
+  if (expr.value()) {
+    debugger->BreakHere();
+  }
+  return Object::null();
+}
+
+
+}  // namespace dart