Revert of [DevTools] Make DevTools clients talk directly to DevToolsAgentHost instead of using DevToolsManage…

extensions/browser/process_manager.cc

Index: extensions/browser/process_manager.cc
diff --git a/extensions/browser/process_manager.cc b/extensions/browser/process_manager.cc
index 1a967ac39a78ddc3e0cff1a3a6f080092b7f9889..fc45e6933cd0ab655e378df13216a20870ce54e4 100644
--- a/extensions/browser/process_manager.cc
+++ b/extensions/browser/process_manager.cc
@@ -16,6 +16,7 @@
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/devtools_agent_host.h"
+#include "content/public/browser/devtools_manager.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/render_frame_host.h"
 #include "content/public/browser/render_process_host.h"
@@ -285,7 +286,8 @@
         base::TimeDelta::FromMilliseconds(suspending_time_msec);
   }
 
-  content::DevToolsAgentHost::AddAgentStateCallback(devtools_callback_);
+  content::DevToolsManager::GetInstance()->AddAgentStateCallback(
+      devtools_callback_);
 
   OnKeepaliveImpulseCheck();
 }
@@ -293,7 +295,8 @@
 ProcessManager::~ProcessManager() {
   CloseBackgroundHosts();
   DCHECK(background_hosts_.empty());
-  content::DevToolsAgentHost::RemoveAgentStateCallback(devtools_callback_);
+  content::DevToolsManager::GetInstance()->RemoveAgentStateCallback(
+      devtools_callback_);
 }
 
 const ProcessManager::ViewSet ProcessManager::GetAllViews() const {