message: When no rows exist, set size to graph row so imgui doesn't take entire window.
diff: @@ -1711,9 +1711,11 @@ void TraceWin::render_process_graphs()
  }
  {
  - const float graph_row_h = 50.0f * gi.scale;
  - const float graph_padding = ImGui::GetStyle().FramePadding.y;
  - const float graph_height = graph_rows * ( graph_row_h + graph_padding );
  + float graph_row_h = 50.0f * gi.scale;
  + float graph_padding = ImGui::GetStyle().FramePadding.y;
  + float graph_height = graph_rows * ( graph_row_h + graph_padding );
  +
  + graph_height = std::max( graph_height, graph_row_h + graph_padding );
  ImGui::BeginChild( "EventGraph", ImVec2( 0, graph_height ), true );
  