[DevTools] Support multiple sessions in content/ domain handlers

content/browser/devtools/protocol/target_handler.cc

Index: content/browser/devtools/protocol/target_handler.cc
diff --git a/content/browser/devtools/protocol/target_handler.cc b/content/browser/devtools/protocol/target_handler.cc
index cff327087bcc912dc1e6f33b3b88509e672933f3..6ce10663f85ae482733daf7d4904b1f9b2b66e01 100644
--- a/content/browser/devtools/protocol/target_handler.cc
+++ b/content/browser/devtools/protocol/target_handler.cc
@@ -106,9 +106,10 @@ TargetHandler::~TargetHandler() {
 }
 
 // static
-TargetHandler* TargetHandler::FromSession(DevToolsSession* session) {
-  return static_cast<TargetHandler*>(
-      session->GetHandlerByName(Target::Metainfo::domainName));
+std::vector<TargetHandler*> TargetHandler::ForAgentHost(
+    DevToolsAgentHostImpl* host) {
+  return DevToolsSession::HandlersForAgentHost<TargetHandler>(
+      host, Target::Metainfo::domainName);
 }
 
 void TargetHandler::Wire(UberDispatcher* dispatcher) {