Dawn: fix SamplerDescriptor params.

Remove comparison function from SamplerDescriptor, to avoid new
validation error.

Also remove other values which are at default.

Change-Id: I99631187f02d6b26748a34cf07c0bc672e2f0607
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/285014
Reviewed-by: Brian Salomon <[email protected]>
Commit-Queue: Stephen White <[email protected]>

Author: SenorBlanco

src/gpu/dawn/GrDawnGpu.cpp

@@ -678,9 +678,6 @@ wgpu::Sampler GrDawnGpu::getOrCreateSampler(GrSamplerState samplerState) {
     desc.addressModeW = wgpu::AddressMode::ClampToEdge;
     desc.magFilter = desc.minFilter = to_dawn_filter_mode(samplerState.filter());
     desc.mipmapFilter = wgpu::FilterMode::Linear;
-    desc.lodMinClamp = 0.0f;
-    desc.lodMaxClamp = 1000.0f;
-    desc.compare = wgpu::CompareFunction::Never;
     wgpu::Sampler sampler = device().CreateSampler(&desc);
     fSamplers.insert(std::pair<GrSamplerState, wgpu::Sampler>(samplerState, sampler));
     return sampler;