Avoid a thread hop when initializing IPC to new processes

content/browser/child_process_launcher.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/child_process_launcher.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/i18n/icu_util.h"
@@ skipping 12 matching lines @@
     std::unique_ptr<base::CommandLine> command_line,
     int child_process_id,
     Client* client,
     std::unique_ptr<mojo::edk::PendingProcessConnection> pending_connection,
     const mojo::edk::ProcessErrorCallback& process_error_callback,
     bool terminate_on_shutdown)
     : client_(client),
       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) || \
     defined(UNDEFINED_SANITIZER)
       terminate_child_on_shutdown_(false),
 #else
       terminate_child_on_shutdown_(terminate_on_shutdown),
 #endif
       weak_factory_(this) {
   DCHECK(CalledOnValidThread());
   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();
 }
 
 ChildProcessLauncher::~ChildProcessLauncher() {
   DCHECK(CalledOnValidThread());
   if (process_.process.IsValid() && terminate_child_on_shutdown_) {
     // Client has gone away, so just kill the process.
     ChildProcessLauncherHelper::ForceNormalProcessTerminationAsync(
         std::move(process_));
   }
 }
 
 void ChildProcessLauncher::SetProcessBackgrounded(bool background) {
   DCHECK(CalledOnValidThread());
   base::Process to_pass = process_.process.Duplicate();
   BrowserThread::PostTask(
       BrowserThread::PROCESS_LAUNCHER, FROM_HERE,
       base::Bind(
           &ChildProcessLauncherHelper::SetProcessBackgroundedOnLauncherThread,
           base::Passed(&to_pass),
           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;
 
     // NOTE: May delete |this|.
     client_->OnProcessLaunchFailed(error_code);
   }
 }
 
 bool ChildProcessLauncher::IsStarting() {
@@ skipping 50 matching lines @@
 }
 
 ChildProcessLauncher::Client* ChildProcessLauncher::ReplaceClientForTest(
     Client* client) {
   Client* ret = client_;
   client_ = client;
   return ret;
 }
 
 }  // namespace content