DevTools: enable target domain handler on the browser target, make browser target non-discoverable.

content/browser/devtools/browser_devtools_agent_host.cc

Index: content/browser/devtools/browser_devtools_agent_host.cc
diff --git a/content/browser/devtools/browser_devtools_agent_host.cc b/content/browser/devtools/browser_devtools_agent_host.cc
index 0d04330f8604b68031c7b6c36ac89be0d2e05e4e..48bc6e7e2122b0672e6e2a9f53ee2b00a6dd6b87 100644
--- a/content/browser/devtools/browser_devtools_agent_host.cc
+++ b/content/browser/devtools/browser_devtools_agent_host.cc
@@ -46,10 +46,10 @@ BrowserDevToolsAgentHost::~BrowserDevToolsAgentHost() {
 }
 
 void BrowserDevToolsAgentHost::AttachSession(DevToolsSession* session) {
-  if (only_discovery_) {
-    session->AddHandler(base::WrapUnique(new protocol::TargetHandler()));
+  session->AddHandler(base::WrapUnique(new protocol::TargetHandler()));
+
+  if (only_discovery_)
     return;
-  }
 
   session->AddHandler(base::WrapUnique(new protocol::IOHandler(
       GetIOContext())));