Avoid a thread hop when initializing IPC to new processes

content/browser/child_process_launcher.cc

Index: content/browser/child_process_launcher.cc
diff --git a/content/browser/child_process_launcher.cc b/content/browser/child_process_launcher.cc
index 3700f47e04cbb73127724b397919d1998f57aba2..686a7206b9928f4c506501136de6b1e42bb22ce4 100644
--- a/content/browser/child_process_launcher.cc
+++ b/content/browser/child_process_launcher.cc
@@ -30,7 +30,6 @@ ChildProcessLauncher::ChildProcessLauncher(
       termination_status_(base::TERMINATION_STATUS_NORMAL_TERMINATION),
       exit_code_(RESULT_CODE_NORMAL_EXIT),
       starting_(true),
-      pending_connection_(std::move(pending_connection)),
       process_error_callback_(process_error_callback),
 #if defined(ADDRESS_SANITIZER) || defined(LEAK_SANITIZER) ||  \
     defined(MEMORY_SANITIZER) || defined(THREAD_SANITIZER) || \
@@ -44,9 +43,10 @@ ChildProcessLauncher::ChildProcessLauncher(
   CHECK(BrowserThread::GetCurrentThreadIdentifier(&client_thread_id_));
 
   helper_ = new ChildProcessLauncherHelper(
-                child_process_id, client_thread_id_,
-              std::move(command_line), std::move(delegate),
-                       weak_factory_.GetWeakPtr(), terminate_on_shutdown);
+      child_process_id, client_thread_id_, std::move(command_line),
+      std::move(delegate), std::move(pending_connection),
+      process_error_callback_, weak_factory_.GetWeakPtr(),
+      terminate_on_shutdown);
   helper_->StartLaunchOnClientThread();
 }
 
@@ -70,24 +70,15 @@ void ChildProcessLauncher::SetProcessBackgrounded(bool background) {
           background));
 }
 
-void ChildProcessLauncher::Notify(
-    ChildProcessLauncherHelper::Process process,
-    mojo::edk::ScopedPlatformHandle server_handle,
-    int error_code) {
+void ChildProcessLauncher::Notify(ChildProcessLauncherHelper::Process process,
+                                  int error_code) {
   DCHECK(CalledOnValidThread());
   starting_ = false;
   process_ = std::move(process);
 
   // Take ownership of the pending connection here so it's destroyed when
   // we go out of scope regardless of the outcome below.
-  std::unique_ptr<mojo::edk::PendingProcessConnection> pending_connection =
-      std::move(pending_connection_);
   if (process_.process.IsValid()) {
-    // Set up Mojo IPC to the new process.
-    DCHECK(pending_connection);
-    pending_connection->Connect(process_.process.Handle(),
-                                std::move(server_handle),
-                                process_error_callback_);
     client_->OnProcessLaunched();
   } else {
     termination_status_ = base::TERMINATION_STATUS_LAUNCH_FAILED;