Replace IOSurfaceManager by directly passing IOSurface Mach ports over Chrome IPC.

ipc/ipc_message_utils.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ipc/ipc_message_utils.h"
 
 #include "base/files/file_path.h"
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/nullable_string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "base/values.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_message_attachment.h"
 #include "ipc/ipc_message_attachment_set.h"
 
 #if defined(OS_POSIX)
 #include "ipc/ipc_platform_file_attachment_posix.h"
 #endif
 
 #if (defined(OS_MACOSX) && !defined(OS_IOS)) || defined(OS_WIN)
 #include "base/memory/shared_memory_handle.h"
 #endif  // (defined(OS_MACOSX) && !defined(OS_IOS)) || defined(OS_WIN)
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
+#include "base/mac/scoped_mach_port.h"
 #include "ipc/mach_port_mac.h"
 #endif
 
 #if defined(OS_WIN)
 #include <tchar.h>
 #include "ipc/handle_win.h"
 #endif
 
 namespace IPC {
 
@@ skipping 999 matching lines @@
 
   return result;
 }
 
 void ParamTraits<MSG>::Log(const param_type& p, std::string* l) {
   l->append("<MSG>");
 }
 
 #endif  // OS_WIN
 
+#if defined(OS_MACOSX) && !defined(OS_IOS)
+void ParamTraits<base::mac::ScopedRefCountedMachSendRight>::Write(
+    Message* m,
+    const param_type p) {
+  MachPortMac mach_port_mac(p.get());
+  ParamTraits<MachPortMac>::Write(m, mach_port_mac);
+}
+
+bool ParamTraits<base::mac::ScopedRefCountedMachSendRight>::Read(

[erikchen, 2015/12/21 20:02:57]

The Chrome IPC stack doesn't have the right semantics to properly support
passing scoped objects.

The code that you've written will work, but implicitly relies on the assumption
that translation only happens once. Attempting to translate a message twice will
result in over-releasing the underlying primitive. Most messages are only
translated once, but some are translated more than once, and more importantly,
there is no enforcement mechanism to ensure single-translation.

I would suggest using MachPortMac directly as the parameter to the IPC message. 

[Robert Sesek, 2015/12/21 20:33:54]

The issue here is that GpuMemoryBufferHandle is both an IPC transit type and an
object used in other ways. Not having the ownership semantics expressed in the
object form I think would make the type extremely easy to misuse (and
underscores ccameron's point). One thing I could do, though, is not offer this
type in base::, but make it more narrowly named for passing IOSurface Mach ports
(e.g., define it in //ui/gfx), where usage may be easier to control. (I also
just have some reservations about adding this type to base:: anyways). WDYT?

+    const Message* m,
+    base::PickleIterator* iter,
+    param_type* r) {
+  MachPortMac mach_port_mac;
+  if (!ParamTraits<MachPortMac>::Read(m, iter, &mach_port_mac))
+    return false;
+  r->reset(mach_port_mac.get_mach_port());
+  return true;
+}
+
+void ParamTraits<base::mac::ScopedRefCountedMachSendRight>::Log(
+    const param_type& p,
+    std::string* l) {
+  l->append("Mach send right: ");
+  LogParam(p.get(), l);
+}
+#endif  // defined(OS_MACOSX) && !defined(OS_IOS)
+
 }  // namespace IPC