Vulkan, Viewports: ImGui_ImplVulkan_RenderDrawData and renderer back-end automatically manage ImGui_ImplVulkanH_WindowRenderBuffers for each viewports so user doesn't have to do it. (#2461, #2348, #2378, #2097)

imgui.cpp

@@ -4000,6 +4000,7 @@ static void SetupViewportDrawData(ImGuiViewportP* viewport, ImVector<ImDrawList*
     draw_data->DisplayPos = viewport->Pos;
     draw_data->DisplaySize = viewport->Size;
     draw_data->FramebufferScale = ImGui::GetIO().DisplayFramebufferScale; // FIXME-VIEWPORT: This may vary on a per-monitor/viewport basis?
+    draw_data->OwnerViewport = viewport;
     for (int n = 0; n < draw_lists->Size; n++)
     {
         draw_data->TotalVtxCount += draw_lists->Data[n]->VtxBuffer.Size;