[mojo-edk] Add support for transferring mach ports.

content/browser/browser_child_process_host_impl.cc

Index: content/browser/browser_child_process_host_impl.cc
diff --git a/content/browser/browser_child_process_host_impl.cc b/content/browser/browser_child_process_host_impl.cc
index 666fdf39e18e714f3b6883c23b1110dbcf3d67b7..2628296bfe7758eec0ed40e1f0cd42d8e4d21174 100644
--- a/content/browser/browser_child_process_host_impl.cc
+++ b/content/browser/browser_child_process_host_impl.cc
@@ -141,6 +141,9 @@ BrowserChildProcessHostImpl::BrowserChildProcessHostImpl(
   IPC::AttachmentBrokerPrivileged::CreateBrokerIfNeeded();
 #endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 #endif  // USE_ATTACHMENT_BROKER
+#if defined(OS_MACOSX) && !defined(OS_IOS)
+  mojo::edk::SetMachPortProviderIfNeeded(MachBroker::GetInstance());

[jam, 2016/03/15 16:27:42]

it doesn't make sense that this code is run each time a child process is
created, given that it's a single time initialization. i realize this just
copies what the previous block does, but i think that's wrong. they should both
be done once in content's browser initialization code, i.e. in
BrowserMainLoop::PostMainMessageLoopStart()

[Anand Mistry (off Chromium), 2016/03/15 20:26:10]

I agree, but I think it should be done to both Mojo and IPC, not just one (it
would be confusing to have IPC here and Mojo elsewhere). I would like to keep
this here for this change, and do a follow up that moves both to
BrowserMainLoop.

[jam, 2016/03/15 23:13:09]

yep I meant do both. can they just be moved in this cl? that should be a small
change

[Anand Mistry (off Chromium), 2016/03/15 23:30:56]

It is small, but this change is already big and complicated. I'd rather leave it
to a separate cl.

+#endif  // defined(OS_MACOSX) && !defined(OS_IOS)
 
   child_process_host_.reset(ChildProcessHost::Create(this));
   AddFilter(new TraceMessageFilter(data_.id));