message: Assert that Metal textures are created
diff: @@ -312,6 +312,7 @@ MetalTexture::MetalTexture(MetalContext& context, backend::SamplerType target, u
  descriptor.usage = getMetalTextureUsage(usage);
  descriptor.storageMode = getMetalStorageMode(usage);
  texture = [context.device newTextureWithDescriptor:descriptor];
  + ASSERT_POSTCONDITION(texture != nil, "Could not create Metal texture. Out of memory?");
  } else if (target == backend::SamplerType::SAMPLER_CUBEMAP) {
  ASSERT_POSTCONDITION(!multisampled, "Multisampled cubemap faces not supported.");
  ASSERT_POSTCONDITION(width == height, "Cubemap faces must be square.");
  @@ -322,6 +323,7 @@ MetalTexture::MetalTexture(MetalContext& context, backend::SamplerType target, u
  descriptor.usage = getMetalTextureUsage(usage);
  descriptor.storageMode = getMetalStorageMode(usage);
  texture = [context.device newTextureWithDescriptor:descriptor];
  + ASSERT_POSTCONDITION(texture != nil, "Could not create Metal texture. Out of memory?");
  } else if (target == backend::SamplerType::SAMPLER_EXTERNAL) {
  // If we're using external textures (CVPixelBufferRefs), we don't need to make any texture
  // allocations.
  