Move attachment broker setup to browser startup.

content/browser/browser_main_loop.cc

Index: content/browser/browser_main_loop.cc
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 9b29b001e512ae50c1501f149c5832bc3e37f12a..c36d820f9dfcc58f788f8c2b46d2c5acaf74ef94 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -98,6 +98,8 @@
 
 #if !defined(OS_IOS)
 #include "content/browser/renderer_host/render_process_host_impl.h"
+#include "ipc/attachment_broker.h"
+#include "ipc/attachment_broker_privileged.h"
 #endif
 
 #if defined(OS_ANDROID)
@@ -117,6 +119,7 @@
 #include "content/browser/bootstrap_sandbox_manager_mac.h"
 #include "content/browser/cocoa/system_hotkey_helper_mac.h"
 #include "content/browser/compositor/browser_compositor_view_mac.h"
+#include "content/browser/mach_broker_mac.h"
 #include "content/browser/theme_helper_mac.h"
 #include "ui/accelerated_widget_mac/window_resize_helper_mac.h"
 #endif
@@ -1200,6 +1203,20 @@ int BrowserMainLoop::BrowserThreadsStarted() {
   mojo_shell_context_.reset(new MojoShellContext);
 #endif
 
+#if USE_ATTACHMENT_BROKER
+  // Construct the privileged attachment broker early.  This ensures that when a
+  // test is being run in one of the single process modes, the global attachment
+  // broker is the privileged attachment broker, rather than an unprivileged
+  // attachment broker.
+#if defined(OS_MACOSX) && !defined(OS_IOS)
+  IPC::AttachmentBrokerPrivileged::CreateBrokerIfNeeded(

[erikchen, 2016/03/16 17:33:11]

It's probably the case that this can just become CreateBroker(), but given the
difficulty of your current work setup, I won't require it.

+      MachBroker::GetInstance());
+  mojo::edk::SetMachPortProviderIfNeeded(MachBroker::GetInstance());
+#else
+  IPC::AttachmentBrokerPrivileged::CreateBrokerIfNeeded();
+#endif  // defined(OS_MACOSX) && !defined(OS_IOS)
+#endif  // USE_ATTACHMENT_BROKER
+
 #if !defined(OS_IOS)
   indexed_db_thread_.reset(new base::Thread("IndexedDB"));
   indexed_db_thread_->Start();