viz: Convert a sync api in ServerGpuMemoryBufferManager into async.

services/ui/ws/gpu_client.cc

Index: services/ui/ws/gpu_client.cc
diff --git a/services/ui/ws/gpu_client.cc b/services/ui/ws/gpu_client.cc
index f5508b363b525967775f2086c73a128ad7de2bef..72e1e4a28ff05367159525424b33ebf2171a830d 100644
--- a/services/ui/ws/gpu_client.cc
+++ b/services/ui/ws/gpu_client.cc
@@ -7,6 +7,15 @@
 #include "components/viz/common/server_gpu_memory_buffer_manager.h"
 #include "services/ui/gpu/interfaces/gpu_service.mojom.h"
 
+namespace {
+
+void RunCallback(const ui::mojom::Gpu::CreateGpuMemoryBufferCallback& callback,
+                 const gfx::GpuMemoryBufferHandle& handle) {
+  callback.Run(handle);
+}
+
+}  // namespace
+
 namespace ui {
 namespace ws {
 
@@ -53,9 +62,9 @@ void GpuClient::CreateGpuMemoryBuffer(
     gfx::BufferFormat format,
     gfx::BufferUsage usage,
     const mojom::Gpu::CreateGpuMemoryBufferCallback& callback) {
-  auto handle = gpu_memory_buffer_manager_->CreateGpuMemoryBufferHandle(
-      id, client_id_, size, format, usage, gpu::kNullSurfaceHandle);
-  callback.Run(handle);
+  gpu_memory_buffer_manager_->AllocateGpuMemoryBuffer(
+      id, client_id_, size, format, usage, gpu::kNullSurfaceHandle,
+      base::BindOnce(&RunCallback, callback));
 }
 
 void GpuClient::DestroyGpuMemoryBuffer(gfx::GpuMemoryBufferId id,