Move dart_debugger into tonic and use it in mojo dart controller

mojo/dart/embedder/monitor.h

-// 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.
-
-#ifndef MOJO_DART_EMBEDDER_MONITOR_H_
-#define MOJO_DART_EMBEDDER_MONITOR_H_
-
-#include "base/synchronization/condition_variable.h"
-#include "base/synchronization/lock.h"
-
-namespace mojo {
-namespace dart {
-
-class Monitor {
- public:
-  Monitor() {
-    lock_ = new base::Lock();
-    condition_variable_ = new base::ConditionVariable(lock_);
-  }
-
-  ~Monitor() {
-    delete condition_variable_;
-    delete lock_;
-  }
-
-  void Enter() {
-    lock_->Acquire();
-  }
-
-  void Exit() {
-    lock_->Release();
-  }
-
-  void Notify() {
-    condition_variable_->Signal();
-  }
-
-  void Wait() {
-    condition_variable_->Wait();
-  }
-
- private:
-  base::Lock* lock_;
-  base::ConditionVariable* condition_variable_;
-  DISALLOW_COPY_AND_ASSIGN(Monitor);
-};
-
-class MonitorLocker {
- public:
-  explicit MonitorLocker(Monitor* monitor) : monitor_(monitor) {
-    CHECK(monitor_);
-    monitor_->Enter();
-  }
-
-  virtual ~MonitorLocker() {
-    monitor_->Exit();
-  }
-
-  void Wait() {
-    return monitor_->Wait();
-  }
-
-  void Notify() {
-    monitor_->Notify();
-  }
-
- private:
-  Monitor* const monitor_;
-
-  DISALLOW_COPY_AND_ASSIGN(MonitorLocker);
-};
-
-}  // namespace dart
-}  // namespace mojo
-
-
-#endif  // MOJO_DART_EMBEDDER_MONITOR_H_