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 eab70cef7d941cdae667e16fdb9dbb2f9a6c59e9..3afbcccda2085a146fef76983b521f51677b02ec 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)
@@ -1206,6 +1208,19 @@ int BrowserMainLoop::BrowserThreadsStarted() {
 #endif  // defined(OS_MACOSX)
 #endif  // !defined(OS_IOS)
 
+#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(
+      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();