Use MailboxManagerSync on android.

services/gles2/mailbox_manager_factory.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 "services/gles2/mailbox_manager_factory.h"
+
+#include "gpu/command_buffer/service/mailbox_manager_impl.h"
+#include "gpu/command_buffer/service/mailbox_manager_sync.h"
+
+namespace gles2 {
+
+gpu::gles2::MailboxManager* MailboxManagerFactory::Create() {
+#if defined(OS_ANDROID)
+  // Use egl fences for synchronization of textures across contexts on android.
+  // TODO(cstout): see if enabling context virtualization removes the need for
+  // fences.
+  return new gpu::gles2::MailboxManagerSync;
+#else
+  return new gpu::gles2::MailboxManagerImpl;
+#endif
+}
+
+}  // namespace gles2