Don't document zero-initializing

That the buffer is zeroed when `age == 0` is not guaranteed, e.g. on
many platforms (Wayland, X11, Web), when we resize the buffer, we don't
also clear it.

We could technically guarantee something like "if the buffer's
underlying data could not be reused, the buffer is zero-initialized",
but that's not really useful to users (at least not unless we expose
additional information in `Buffer::age`).

This might also make it easier to use zero-copying on Android (might be
able to avoid having to clear the buffer).

Author: madsmtm

src/lib.rs

@@ -197,7 +197,7 @@ impl<D: HasDisplayHandle, W: HasWindowHandle> Surface<D, W> {
     ///
     /// The size must be set with [`Surface::resize`] or [`Surface::configure`] first.
     ///
-    /// The contents of the buffer may be zeroed, or may contain a previous frame. Call
+    /// The contents of the buffer may be garbage, or may contain a previous frame. Call
     /// [`Buffer::age`] to determine this.
     ///
     /// ## Platform Dependent Behavior