hello-triangle tries to configure with zero size on web

[kpreid]

Description
When hello-triangle starts up under wasm, it configures the surface with window.inner_size(), but that size is zero. Furthermore, the WebGPU backend does not catch this validation error.

Repro steps

cargo xtask run-wasm --bin hello-triangle
cargo xtask run-wasm --bin hello-triangle --features webgl

Expected vs observed behavior

• The example should not configure with zero size. (Is this a winit bug that the canvas size is incorrectly reported?)

• This should be a validation error on all backends, or succeed on all backends. Instead, on WebGPU this does not produce a wgpu validation error, but produces a validation error from the underlying WebGPU, and rendering then succeeds later.

  The texture size ([Extent3D width:0, height:0, depthOrArrayLayers:1]) or mipLevelCount (1) is empty.
  at ValidateTextureDescriptor (../../third_party/dawn/src/dawn/native/Texture.cpp:478)
  

  On WebGL it panics with a validation error inside wgpu.

Platform

• Chrome 118.0.5993.88
• macOS x86_64-apple-darwin
• wgpu trunk b6fa2c5

[cwfitzgerald]

The WebGPU issue is #3675