ozone: ClientPixmapManager passes VGEM fd from browser to renderer.

content/child/child_io_surface_manager_mac.cc

 // Copyright 2015 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 "content/child/child_io_surface_manager_mac.h"
 
 #include "base/mac/mach_logging.h"
 #include "content/common/mac/io_surface_manager_messages.h"
 
 namespace content {
@@ skipping 78 matching lines @@
     MACH_LOG(ERROR, kr) << "mach_msg";
   }
 }
 
 IOSurfaceRef ChildIOSurfaceManager::AcquireIOSurface(int io_surface_id) {
   DCHECK(service_port_.is_valid());
 
   // A valid token is required to acquire an IOSurface. This will wait for a
   // valid token if one has not yet been set.
   set_token_event_.Wait();
-#if !defined(NDEBUG)
+#if DCHECK_IS_ON()
   DCHECK(!(set_token_thread_id_ == base::PlatformThread::CurrentRef()));

[dshwang, 2015/08/18 16:15:34]

I rollback to PlatformThreadRef. I don't use base::Lock because
base::WaitableEvent makes sure visibility before this line.
Thank you for patient explanation.

 #endif
   DCHECK(!token_.IsZero());
 
   mach_port_t reply_port;
   kern_return_t kr = mach_port_allocate(mach_task_self(),
                                         MACH_PORT_RIGHT_RECEIVE, &reply_port);
   if (kr != KERN_SUCCESS) {
     MACH_LOG(ERROR, kr) << "mach_port_allocate";
     return nullptr;
   }
@@ skipping 30 matching lines @@
   return IOSurfaceLookupFromMachPort(scoped_io_surface_right);
 }
 
 ChildIOSurfaceManager::ChildIOSurfaceManager()
     : set_token_event_(true, false) {}
 
 ChildIOSurfaceManager::~ChildIOSurfaceManager() {
 }
 
 }  // namespace content