[DevTools] Migrate from AgentStateCallbacks to DevToolsAgentHostObserver.

content/browser/devtools/render_frame_devtools_agent_host.cc

 // Copyright (c) 2012 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.
 
 #include "content/browser/devtools/render_frame_devtools_agent_host.h"
 
 #include <tuple>
 #include <utility>
 
 #include "base/guid.h"
@@ skipping 515 matching lines @@
   if (pending_)
     pending_->InspectElement(session_id(), x, y);
 }
 
 void RenderFrameDevToolsAgentHost::OnClientAttached() {
   if (!web_contents())
     return;
 
   frame_trace_recorder_.reset(new DevToolsFrameTraceRecorder());
   CreatePowerSaveBlocker();
-
-  // TODO(kaznacheev): Move this call back to DevToolsManager when
-  // extensions::ProcessManager no longer relies on this notification.
-  DevToolsAgentHostImpl::NotifyCallbacks(this, true);
 }
 
 void RenderFrameDevToolsAgentHost::OnClientDetached() {
 #if defined(OS_ANDROID)
   power_save_blocker_.reset();
 #endif
   browser_handler_->Detached();
   if (emulation_handler_)
     emulation_handler_->Detached();
   if (page_handler_)
     page_handler_->Detached();
   service_worker_handler_->Detached();
   target_handler_->Detached();
   tracing_handler_->Detached();
   frame_trace_recorder_.reset();
   in_navigation_protocol_message_buffer_.clear();
-
-  // TODO(kaznacheev): Move this call back to DevToolsManager when
-  // extensions::ProcessManager no longer relies on this notification.
-  DevToolsAgentHostImpl::NotifyCallbacks(this, false);
 }
 
 RenderFrameDevToolsAgentHost::~RenderFrameDevToolsAgentHost() {
   Instances::iterator it = std::find(g_instances.Get().begin(),
                                      g_instances.Get().end(),
                                      this);
   if (it != g_instances.Get().end())
     g_instances.Get().erase(it);
 }
 
@@ skipping 524 matching lines @@
     RenderFrameHost* host) {
   return (current_ && current_->host() == host) ||
       (pending_ && pending_->host() == host);
 }
 
 bool RenderFrameDevToolsAgentHost::IsChildFrame() {
   return current_ && current_->host()->GetParent();
 }
 
 }  // namespace content