content: Pass IOSurface references using Mach IPC.

content/browser/renderer_host/render_process_host_impl.h

Index: content/browser/renderer_host/render_process_host_impl.h
diff --git a/content/browser/renderer_host/render_process_host_impl.h b/content/browser/renderer_host/render_process_host_impl.h
index e7c8d94fedb5b04951127fcafcb925999bf88567..001975664f964b88fe8bbb6b332a4335c235f728 100644
--- a/content/browser/renderer_host/render_process_host_impl.h
+++ b/content/browser/renderer_host/render_process_host_impl.h
@@ -24,6 +24,10 @@
 #include "ui/gfx/gpu_memory_buffer.h"
 #include "ui/gl/gpu_switching_observer.h"
 
+#if defined(OS_MACOSX) && !defined(OS_IOS)
+#include "gpu/command_buffer/common/mailbox.h"
+#endif
+
 namespace base {
 class CommandLine;
 class MessageLoop;
@@ -500,6 +504,10 @@ class CONTENT_EXPORT RenderProcessHostImpl
   // Whether or not the CHROMIUM_subscribe_uniform WebGL extension is enabled
   bool subscribe_uniform_enabled_;
 
+#if defined(OS_MACOSX) && !defined(OS_IOS)
+  gpu::Mailbox io_surface_manager_mailbox_;
+#endif
+
   base::WeakPtrFactory<RenderProcessHostImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderProcessHostImpl);