Add the UI compositor to the Mac build

content/browser/compositor/owned_mailbox.cc

Index: content/browser/compositor/owned_mailbox.cc
diff --git a/content/browser/aura/owned_mailbox.cc b/content/browser/compositor/owned_mailbox.cc
similarity index 90%
rename from content/browser/aura/owned_mailbox.cc
rename to content/browser/compositor/owned_mailbox.cc
index 5994903b33220a908dba061a304f1830e535f6c1..0211800800894e7061252f7536823e386ff51932 100644
--- a/content/browser/aura/owned_mailbox.cc
+++ b/content/browser/compositor/owned_mailbox.cc
@@ -2,10 +2,10 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "content/browser/aura/owned_mailbox.h"
+#include "content/browser/compositor/owned_mailbox.h"
 
 #include "base/logging.h"
-#include "content/browser/aura/image_transport_factory.h"
+#include "content/browser/compositor/image_transport_factory.h"
 #include "content/common/gpu/client/gl_helper.h"
 
 namespace content {