[DevTools] Rework idle{Started,Finished} instrumentation.

third_party/WebKit/Source/platform/v8_inspector/public/V8ProfilerAgent.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 V8ProfilerAgent_h
 #define V8ProfilerAgent_h
 
 #include "platform/PlatformExport.h"
 #include "platform/inspector_protocol/Dispatcher.h"
 #include "platform/v8_inspector/public/V8Debugger.h"
 
 namespace blink {
 
 class PLATFORM_EXPORT V8ProfilerAgent : public protocol::Backend::Profiler, public V8Debugger::Agent<protocol::Frontend::Profiler> {
 public:
     virtual ~V8ProfilerAgent() { }
-
-    virtual void idleStarted() = 0;
-    virtual void idleFinished() = 0;
 };
 
 } // namespace blink
 
 
 #endif // !defined(V8ProfilerAgent_h)