ui: Add libsync GLFence implementation.

gpu/ipc/service/gpu_channel.cc

Index: gpu/ipc/service/gpu_channel.cc
diff --git a/gpu/ipc/service/gpu_channel.cc b/gpu/ipc/service/gpu_channel.cc
index 2c672d6d4bc6454e7ee2ebe342a07f36ca6513d1..60838010ba0fb741c63571120506c71d6a7e5e26 100644
--- a/gpu/ipc/service/gpu_channel.cc
+++ b/gpu/ipc/service/gpu_channel.cc
@@ -51,6 +51,10 @@
 #include "ipc/ipc_channel_posix.h"
 #endif
 
+#if defined(OS_LINUX)
+#include "ui/gl/gl_fence_libsync.h"
+#endif
+
 namespace gpu {
 namespace {
 
@@ -1072,6 +1076,12 @@ scoped_refptr<gl::GLImage> GpuChannel::CreateImageForGpuMemoryBuffer(
 
 std::unique_ptr<gl::GLFence> GpuChannel::CreateFenceForGpuFence(
     const gfx::GpuFenceHandle& handle) {
+#if defined(OS_LINUX)
+  base::ScopedFD libsync_fd(handle.fd.fd);
+  if (libsync_fd.is_valid())
+    return base::MakeUnique<gl::GLFenceLibsync>(std::move(libsync_fd));
+#endif
+
   return base::MakeUnique<gl::GLFenceSharedEvent>(handle.shared_event_handle);
 }