[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 5ba8c13eadf7a7db18e2efcd88c2adaa300c43c7..aa8269b8f17641703d66ffad28f71f58551de63f 100644
--- a/extensions/browser/process_manager.cc
+++ b/extensions/browser/process_manager.cc
@@ -16,7 +16,6 @@
 #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"
@@ -286,8 +285,7 @@ ProcessManager::ProcessManager(BrowserContext* context,
         base::TimeDelta::FromMilliseconds(suspending_time_msec);
   }
 
-  content::DevToolsManager::GetInstance()->AddAgentStateCallback(
-      devtools_callback_);
+  content::DevToolsAgentHost::AddAgentStateCallback(devtools_callback_);
 
   OnKeepaliveImpulseCheck();
 }
@@ -295,8 +293,7 @@ ProcessManager::ProcessManager(BrowserContext* context,
 ProcessManager::~ProcessManager() {
   CloseBackgroundHosts();
   DCHECK(background_hosts_.empty());
-  content::DevToolsManager::GetInstance()->RemoveAgentStateCallback(
-      devtools_callback_);
+  content::DevToolsAgentHost::RemoveAgentStateCallback(devtools_callback_);
 }
 
 const ProcessManager::ViewSet ProcessManager::GetAllViews() const {