Add "Supports overlays" information to about:gpu.

gpu/config/gpu_info.h

Index: gpu/config/gpu_info.h
diff --git a/gpu/config/gpu_info.h b/gpu/config/gpu_info.h
index d736ee3f077a7345e6506820dd52a05d2a43ee6b..9460724aded25debe993005a97d16f9a632746b3 100644
--- a/gpu/config/gpu_info.h
+++ b/gpu/config/gpu_info.h
@@ -217,6 +217,9 @@ struct GPU_EXPORT GPUInfo {
   // True if the GPU process is using the passthrough command decoder.
   bool passthrough_cmd_decoder;
 
+  // True if the current set of outputs supports overlays.
+  bool supports_overlays = false;
+
   // The state of whether the basic/context/DxDiagnostics info is collected and
   // if the collection fails or not.
   CollectInfoResult basic_info_state;