[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..eb99544a4a6a851e3f580e7c2904a28da48af2a6 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() {
@@ -184,6 +185,9 @@ void SystemInfoHandler::Wire(UberDispatcher* dispatcher) {
   SystemInfo::Dispatcher::wire(dispatcher, this);
 }
 
+void SystemInfoHandler::SetRenderFrameHost(RenderFrameHostImpl* host) {
+}
+
 Response SystemInfoHandler::Disable() {
   return Response::OK();
 }