Revert of Add EnabledStateObserver to BackgroundTracingManager

content/browser/tracing/background_memory_tracing_observer.h

Index: content/browser/tracing/background_memory_tracing_observer.h
diff --git a/content/browser/tracing/background_memory_tracing_observer.h b/content/browser/tracing/background_memory_tracing_observer.h
deleted file mode 100644
index abd7e92d8de2f2cab8123582f3ab8168395a64c2..0000000000000000000000000000000000000000
--- a/content/browser/tracing/background_memory_tracing_observer.h
+++ /dev/null
@@ -1,30 +0,0 @@
-// Copyright 2017 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_MEMORY_TRACING_OBSERVER_H_
-#define CONTENT_BROWSER_TRACING_BACKGROUND_MEMORY_TRACING_OBSERVER_H_
-
-#include "content/browser/tracing/background_tracing_manager_impl.h"
-
-namespace content {
-
-class BackgroundMemoryTracingObserver
-    : public BackgroundTracingManagerImpl::EnabledStateObserver {
- public:
-  static BackgroundMemoryTracingObserver* GetInstance();
-
-  void OnScenarioActivated(const BackgroundTracingConfigImpl& config) override;
-  void OnTracingEnabled(
-      BackgroundTracingConfigImpl::CategoryPreset preset) override;
-
- private:
-  BackgroundMemoryTracingObserver();
-  ~BackgroundMemoryTracingObserver() override;
-
-  DISALLOW_COPY_AND_ASSIGN(BackgroundMemoryTracingObserver);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_TRACING_BACKGROUND_MEMORY_TRACING_OBSERVER_H_