Revert of arc: enable Android tracing from chrome://tracing in dev mode

content/browser/tracing/arc_tracing_agent.h

-// 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_ARC_TRACING_AGENT_H_
-#define CONTENT_BROWSER_TRACING_ARC_TRACING_AGENT_H_
-
-#include "base/callback_forward.h"
-#include "base/macros.h"
-#include "base/trace_event/trace_event.h"
-#include "base/trace_event/tracing_agent.h"
-
-namespace content {
-
-// A wrapper for controlling tracing in ARC container.
-// The overriden Stop/StartAgentTracing functions are implemented by the
-// Delegate object to interact with ARC bridge. All the functions are expected
-// to be called on the browser's UI thread.
-class ArcTracingAgent : public base::trace_event::TracingAgent {
- public:
-  class Delegate {
-   public:
-    // Callback for StartTracing, takes one boolean argument to indicate
-    // success or failure.
-    using StartTracingCallback = base::Callback<void(bool)>;
-    // Callback for StopTracing, takes one boolean argument to indicate
-    // success or failure.
-    using StopTracingCallback = base::Callback<void(bool)>;
-
-    virtual ~Delegate();
-
-    // Starts tracing in ARC container.
-    virtual void StartTracing(
-        const base::trace_event::TraceConfig& trace_config,
-        const StartTracingCallback& callback) = 0;
-
-    // Stops tracing in ARC container.
-    virtual void StopTracing(const StopTracingCallback& callback) = 0;
-  };
-
-  ArcTracingAgent();
-  ~ArcTracingAgent() override;
-
-  static ArcTracingAgent* GetInstance();
-
-  // Sets Delegate instance, which should implement the communication
-  // using ARC bridge. If set to nullptr, calling of Start/StopAgentTracing
-  // does nothing. Ownership of |delegate| remains with the caller.
-  virtual void SetDelegate(Delegate* delegate) = 0;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(ArcTracingAgent);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_TRACING_ARC_TRACING_AGENT_H_