Vulkan: Enable some more fbo.render dEQP tests

Sometime we have a clear call with clearDepth+clearStencil but no
attachment to clear. This was triggering the assert instead of
just skipping the clear.

Bug: angleproject:2597
Change-Id: I2d7750db919afe47cf02155f7c4afd0b02318bb1
Reviewed-on: https://chromium-review.googlesource.com/1106039
Commit-Queue: Luc Ferron <lucferron@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/FramebufferVk.cpp b/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
index a387961..83bace0 100644
--- a/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
+++ b/src/libANGLE/renderer/vulkan/FramebufferVk.cpp
@@ -176,9 +176,6 @@
         const VkClearDepthStencilValue &clearDepthStencilValue =
             contextVk->getClearDepthStencilValue().depthStencil;
 
-        // We only support packed depth/stencil, not separate.
-        ASSERT(!(clearDepth && clearStencil) || depthStencilAttachment);
-
         const VkImageAspectFlags aspectFlags =
             (depthAttachment ? VK_IMAGE_ASPECT_DEPTH_BIT : 0) |
             (stencilAttachment ? VK_IMAGE_ASPECT_STENCIL_BIT : 0);
@@ -186,14 +183,13 @@
         RenderTargetVk *renderTarget = mRenderTargetCache.getDepthStencil();
         vk::ImageHelper *image       = renderTarget->getImageForWrite(currentSerial, this);
         image->clearDepthStencil(aspectFlags, clearDepthStencilValue, commandBuffer);
-
-        if (!clearColor)
-        {
-            return gl::NoError();
-        }
     }
 
-    ASSERT(clearColor);
+    if (!clearColor)
+    {
+        return gl::NoError();
+    }
+
     const auto *attachment = mState.getFirstNonNullAttachment();
     ASSERT(attachment && attachment->isAttached());