Mojo EDK: Work around Nexus 9 hardware bug

mojo/edk/system/ports/node.cc

 // Copyright 2016 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 "mojo/edk/system/ports/node.h"
 
 #include <string.h>
 
 #include <utility>
 
+#include "base/atomicops.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "mojo/edk/system/ports/node_delegate.h"
 
 namespace mojo {
 namespace edk {
 namespace ports {
 
 namespace {
@@ skipping 776 matching lines @@
   base::AutoLock lock(ports_lock_);
   return GetPort_Locked(port_name);
 }
 
 scoped_refptr<Port> Node::GetPort_Locked(const PortName& port_name) {
   ports_lock_.AssertAcquired();
   auto iter = ports_.find(port_name);
   if (iter == ports_.end())
     return nullptr;
 
+#if defined(OS_ANDROID)

[Torne, 2016/11/18 15:37:57]

You could use #if defined(OS_ANDROID) && defined(ARCH_CPU_ARM64) to limit it
more specifically.

[Ken Rockot(use gerrit already), 2016/11/18 15:49:28]

Done

+  // Workaround for https://crbug.com/665869.
+  base::subtle::MemoryBarrier();
+#endif
+
   return iter->second;
 }
 
 int Node::SendMessageInternal(const PortRef& port_ref, ScopedMessage* message) {
   ScopedMessage& m = *message;
   for (size_t i = 0; i < m->num_ports(); ++i) {
     if (m->ports()[i] == port_ref.name())
       return ERROR_PORT_CANNOT_SEND_SELF;
   }
 
@@ skipping 555 matching lines @@
 
   if (num_data_bytes)
     memcpy(header + 1, data, num_data_bytes);
 
   return message;
 }
 
 }  // namespace ports
 }  // namespace edk
 }  // namespace mojo