[escher] Use depth format supported by current device in FramebufferAllocatorTest.

Instead of always disabling depth texture creation, we should use a depth format
supported by current GPU device instead.

TEST=escher_unittests

Change-Id: Idf29efa4bac9c8859722989e6f6130bdae5c211d
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/559621
Reviewed-by: Josh Gargus <jjosh@google.com>
Commit-Queue: Yilong Li <liyl@google.com>
diff --git a/src/ui/lib/escher/test/vk/framebuffer_allocator_unittest.cc b/src/ui/lib/escher/test/vk/framebuffer_allocator_unittest.cc
index 97db0a7..faf2d5a 100644
--- a/src/ui/lib/escher/test/vk/framebuffer_allocator_unittest.cc
+++ b/src/ui/lib/escher/test/vk/framebuffer_allocator_unittest.cc
@@ -224,12 +224,14 @@
   // Make a single set of textures (depth and 2 color attachments) that will be
   // used to make a framebuffer.
   auto depth_format_result = escher->device()->caps().GetMatchingDepthFormat();
+  vk::Format depth_format = depth_format_result.value;
   if (depth_format_result.result != vk::Result::eSuccess) {
     FX_LOGS(ERROR) << "No depth stencil format is supported on this device.";
+    depth_format = vk::Format::eUndefined;
   }
 
   auto textures = MakeFramebufferTextures(escher, 1, kWidth, kHeight, 1, vk::Format::eB8G8R8A8Unorm,
-                                          vk::Format::eB8G8R8A8Unorm, vk::Format::eUndefined);
+                                          vk::Format::eB8G8R8A8Unorm, depth_format);
   auto framebuffer = ObtainFramebuffers(&allocator, textures);
 
   // Obtaining a Framebuffer using the same textures should result in the same
@@ -280,11 +282,11 @@
 
   auto textures_bgra =
       MakeFramebufferTextures(escher, 2, kWidth, kHeight, 1, vk::Format::eB8G8R8A8Unorm,
-                              vk::Format::eB8G8R8A8Unorm, vk::Format::eUndefined);
+                              vk::Format::eB8G8R8A8Unorm, depth_format);
 
   auto textures_rgba =
       MakeFramebufferTextures(escher, 1, kWidth, kHeight, 1, vk::Format::eR8G8B8A8Unorm,
-                              vk::Format::eR8G8B8A8Unorm, vk::Format::eUndefined);
+                              vk::Format::eR8G8B8A8Unorm, depth_format);
 
   RenderPassInfo rpi_bgra0 = MakeRenderPassInfo(textures_bgra[0]);
   RenderPassInfo rpi_bgra1 = MakeRenderPassInfo(textures_bgra[1]);