[Try # 3] Scheduler refactoring to virtually eliminate redundant DoWorks

third_party/WebKit/Source/platform/scheduler/base/moveable_auto_lock.h

+// Copyright 2016 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 THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_BASE_MOVEABLE_AUTO_LOCK_H_
+#define THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_BASE_MOVEABLE_AUTO_LOCK_H_
+
+#include "base/synchronization/lock.h"
+
+namespace blink {
+namespace scheduler {
+
+class MoveableAutoLock {
+ public:
+  explicit MoveableAutoLock(base::Lock& lock) : lock_(lock), moved_(false) {
+    lock_.Acquire();
+  }
+
+  explicit MoveableAutoLock(MoveableAutoLock&& other)
+      : lock_(other.lock_), moved_(other.moved_) {
+    lock_.AssertAcquired();
+    other.moved_ = true;
+  }
+
+  ~MoveableAutoLock() {
+    if (moved_)
+      return;
+    lock_.AssertAcquired();
+    lock_.Release();
+  }
+
+ private:
+  base::Lock& lock_;
+  bool moved_;
+  DISALLOW_COPY_AND_ASSIGN(MoveableAutoLock);
+};
+
+}  // namespace scheduler
+}  // namespace blink
+
+#endif  // THIRD_PARTY_WEBKIT_SOURCE_PLATFORM_SCHEDULER_BASE_MOVEABLE_AUTO_LOCK_H_