Vulkan: Use DontCare for the presentable surface's last renderpass depth/stencil storeOp

src/libANGLE/renderer/vulkan/ContextVk.cpp

@@ -2380,6 +2380,17 @@ void ContextVk::optimizeRenderPassForPresent(VkFramebuffer framebufferHandle)
         return;
     }
 
+    // EGL1.5 spec: The contents of ancillary buffers are always undefined after calling
+    // eglSwapBuffers
+    RenderTargetVk *depthStencilRenderTarget = mDrawFramebuffer->getDepthStencilRenderTarget();
+    if (depthStencilRenderTarget)
+    {
+        size_t depthStencilAttachmentIndexVk = mDrawFramebuffer->getDepthStencilAttachmentIndexVk();
+        // Change depthstencil attachment storeOp to DONT_CARE
+        mRenderPassCommands.invalidateRenderPassStencilAttachment(depthStencilAttachmentIndexVk);
+        mRenderPassCommands.invalidateRenderPassDepthAttachment(depthStencilAttachmentIndexVk);
+    }
+
     // Use finalLayout instead of extra barrier for layout change to present
     vk::ImageHelper &image = color0RenderTarget->getImage();
     image.setCurrentImageLayout(vk::ImageLayout::Present);

src/libANGLE/renderer/vulkan/FramebufferVk.h

@@ -119,6 +119,12 @@ class FramebufferVk : public FramebufferImpl
 
     const vk::RenderPassDesc &getRenderPassDesc() const { return mRenderPassDesc; }
     const vk::FramebufferDesc &getFramebufferDesc() const { return mCurrentFramebufferDesc; }
+    // We only support depth/stencil packed format and depthstencil attachment always follow all
+    // color attachments
+    size_t getDepthStencilAttachmentIndexVk() const
+    {
+        return getState().getEnabledDrawBuffers().count();
+    }
 
   private:
     FramebufferVk(RendererVk *renderer,