Re-land first pass BackgroundTracingManager.

content/browser/tracing/background_tracing_endpoint.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 CONTENT_BROWSER_TRACING_BACKGROUND_TRACING_ENDPOINT_H_
+#define CONTENT_BROWSER_TRACING_BACKGROUND_TRACING_ENDPOINT_H_
+
+#include "base/callback.h"
+#include "content/common/content_export.h"
+#include "content/public/browser/tracing_controller.h"
+
+class CONTENT_EXPORT BackgroundTracingEndpoint
+    : public content::TracingController::TraceDataEndpoint {
+ public:
+  BackgroundTracingEndpoint();
+
+  typedef base::Callback<void()> DoneCallback;
+
+  void SetDoneCallback(DoneCallback callback);
+
+ protected:
+  ~BackgroundTracingEndpoint() override;
+
+  DoneCallback done_callback_;
+
+  friend class base::RefCountedThreadSafe<BackgroundTracingEndpoint>;
+};
+
+#endif  // CONTENT_BROWSER_TRACING_BACKGROUND_TRACING_ENDPOINT_H_