gpu: Add GpuFence framework.

ui/aura/mus/mojo_gpu_memory_buffer_manager.cc

Index: ui/aura/mus/mojo_gpu_memory_buffer_manager.cc
diff --git a/ui/aura/mus/mojo_gpu_memory_buffer_manager.cc b/ui/aura/mus/mojo_gpu_memory_buffer_manager.cc
index ff5a7c7d305b0c95f84aab8e2d0b0303d29f1e2d..3e25788dd0661a52393a2180eaa86040a042fea3 100644
--- a/ui/aura/mus/mojo_gpu_memory_buffer_manager.cc
+++ b/ui/aura/mus/mojo_gpu_memory_buffer_manager.cc
@@ -37,4 +37,22 @@ void MojoGpuMemoryBufferManager::SetDestructionSyncToken(
   NOTIMPLEMENTED();
 }
 
+std::unique_ptr<gfx::GpuFence> MojoGpuMemoryBufferManager::CreateGpuFence() {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+std::unique_ptr<gfx::GpuFence>
+MojoGpuMemoryBufferManager::CreateGpuFenceFromHandle(
+    const gfx::GpuFenceHandle& handle) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+gfx::GpuFence* MojoGpuMemoryBufferManager::GpuFenceFromClientFence(
+    ClientFence fence) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
 }  // namespace aura