gpu: Add GpuFence framework.

services/ui/ws/mus_gpu_memory_buffer_manager.cc

Index: services/ui/ws/mus_gpu_memory_buffer_manager.cc
diff --git a/services/ui/ws/mus_gpu_memory_buffer_manager.cc b/services/ui/ws/mus_gpu_memory_buffer_manager.cc
index 1dae509d8a1379ff0be5d2435644ba85e4be364d..e2b167d4afc7baa7ec34527497e295a233a008d5 100644
--- a/services/ui/ws/mus_gpu_memory_buffer_manager.cc
+++ b/services/ui/ws/mus_gpu_memory_buffer_manager.cc
@@ -67,6 +67,24 @@ void MusGpuMemoryBufferManager::SetDestructionSyncToken(
       sync_token);
 }
 
+std::unique_ptr<gfx::GpuFence> MusGpuMemoryBufferManager::CreateGpuFence() {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+std::unique_ptr<gfx::GpuFence>
+MusGpuMemoryBufferManager::CreateGpuFenceFromHandle(
+    const gfx::GpuFenceHandle& handle) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+gfx::GpuFence* MusGpuMemoryBufferManager::GpuFenceFromClientFence(
+    ClientFence fence) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
 void MusGpuMemoryBufferManager::DestroyGpuMemoryBuffer(
     gfx::GpuMemoryBufferId id,
     int client_id,