[DevTools] Rework DevToolsSession interaction with domain handlers.

content/browser/devtools/protocol/system_info_handler.cc

Index: content/browser/devtools/protocol/system_info_handler.cc
diff --git a/content/browser/devtools/protocol/system_info_handler.cc b/content/browser/devtools/protocol/system_info_handler.cc
index 8ad8b94a180fcc42bf0daa5259829e30f082bd68..f0abfc1a20d72b7170344dfe5b6dfcf9b09e0a2c 100644
--- a/content/browser/devtools/protocol/system_info_handler.cc
+++ b/content/browser/devtools/protocol/system_info_handler.cc
@@ -174,7 +174,8 @@ class SystemInfoHandlerGpuObserver : public content::GpuDataManagerObserver {
   base::WeakPtrFactory<SystemInfoHandlerGpuObserver> weak_factory_;
 };
 
-SystemInfoHandler::SystemInfoHandler() {
+SystemInfoHandler::SystemInfoHandler()
+    : DevToolsDomainHandler(SystemInfo::Metainfo::domainName) {
 }
 
 SystemInfoHandler::~SystemInfoHandler() {
@@ -184,10 +185,6 @@ void SystemInfoHandler::Wire(UberDispatcher* dispatcher) {
   SystemInfo::Dispatcher::wire(dispatcher, this);
 }
 
-Response SystemInfoHandler::Disable() {
-  return Response::OK();
-}
-
 void SystemInfoHandler::GetInfo(
     std::unique_ptr<GetInfoCallback> callback) {
   std::string reason;