gpu: Add GpuFence framework.

blimp/client/support/compositor/blimp_gpu_memory_buffer_manager.cc

Index: blimp/client/support/compositor/blimp_gpu_memory_buffer_manager.cc
diff --git a/blimp/client/support/compositor/blimp_gpu_memory_buffer_manager.cc b/blimp/client/support/compositor/blimp_gpu_memory_buffer_manager.cc
index 4c39ffad2e33f321b37b9a9fa6faaefe6b551f0b..755125ba94e3f903452d2388a37e90f33d3f6452 100644
--- a/blimp/client/support/compositor/blimp_gpu_memory_buffer_manager.cc
+++ b/blimp/client/support/compositor/blimp_gpu_memory_buffer_manager.cc
@@ -156,5 +156,23 @@ void BlimpGpuMemoryBufferManager::SetDestructionSyncToken(
   NOTIMPLEMENTED();
 }
 
+std::unique_ptr<gfx::GpuFence> BlimpGpuMemoryBufferManager::CreateGpuFence() {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+std::unique_ptr<gfx::GpuFence>
+BlimpGpuMemoryBufferManager::CreateGpuFenceFromHandle(
+    const gfx::GpuFenceHandle& handle) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+gfx::GpuFence* BlimpGpuMemoryBufferManager::GpuFenceFromClientFence(
+    ClientFence fence) {
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
 }  // namespace client
 }  // namespace blimp