Add a mechanism to let TracingController invoke JavaScript via TracingUI

content/public/browser/tracing_controller.h

 // Copyright 2013 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_PUBLIC_BROWSER_TRACING_CONTROLLER_H_
 #define CONTENT_PUBLIC_BROWSER_TRACING_CONTROLLER_H_
 
 #include <set>
 #include <string>
 
 #include "base/callback.h"
 #include "content/common/content_export.h"
 
 namespace base {
 class FilePath;
 };
 
 namespace content {
 
 class TracingController;
+class TracingUI;
 
 // TracingController is used on the browser processes to enable/disable
 // trace status and collect trace data. Only the browser UI thread is allowed
 // to interact with the TracingController object. All callbacks are called on
 // the UI thread.
 class TracingController {
  public:
   enum Options {
     DEFAULT_OPTIONS = 0,
     ENABLE_SYSTRACE = 1 << 0,
@@ skipping 123 matching lines @@
   // process.
   typedef base::Callback<void()> WatchEventCallback;
   virtual bool SetWatchEvent(const std::string& category_name,
                              const std::string& event_name,
                              const WatchEventCallback& callback) = 0;
 
   // Cancel the watch event. If tracing is enabled, this may race with the
   // watch event callback.
   virtual bool CancelWatchEvent() = 0;
 
+  // Regsiter/Unregister tracing UI that is using this TracingController.

[dsinclair, 2014/01/08 15:57:27]

nit: s/Regsiter/Register

+  virtual void RegisterTracingUI(TracingUI* tracing_ui) = 0;
+  virtual void UnregisterTracingUI(TracingUI* tracing_ui) = 0;
+
  protected:
   virtual ~TracingController() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_TRACING_CONTROLLER_H_