Add COPY_SRC to Metal's surface usage bits. (#4852)

CHANGELOG.md

@@ -189,6 +189,10 @@ Passing an owned value `window` to `Surface` will return a `Surface<'static>`. S
 
 - Record the names of WGSL `alias` declarations in Naga IR `Type`s. By @jimblandy in [#4733](https://github.com/gfx-rs/wgpu/pull/4733).
 
+#### Metal
+
+- Allow the `COPY_SRC` usage flag in surface configuration. By @Toqozz in [#4852](https://github.com/gfx-rs/wgpu/pull/4852).
+
 ### Examples
 
 - remove winit dependency from hello-compute example by @psvri in [#4699](https://github.com/gfx-rs/wgpu/pull/4699)

wgpu-hal/src/metal/adapter.rs

@@ -339,7 +339,9 @@ impl crate::Adapter<super::Api> for super::Adapter {
             ],
 
             current_extent,
-            usage: crate::TextureUses::COLOR_TARGET | crate::TextureUses::COPY_DST, //TODO: expose more
+            usage: crate::TextureUses::COLOR_TARGET
+                | crate::TextureUses::COPY_SRC
+                | crate::TextureUses::COPY_DST,
         })
     }