Auto merge of #20420 - pyfisch:corner-clipping, r=emilio

Move DL items from gfx to layout and implement corner clipping

Implement corner clipping.
Remove PixelFormat from WebrenderImageInfo.
Use WebRender text shadow.
Remove MallocSizeOf and Deserialize for DL items.

Closes #19649, closes #19680, closes #19802

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components/gfx/lib.rs

@@ -43,14 +43,11 @@ extern crate lazy_static;
 extern crate log;
 #[cfg_attr(target_os = "windows", macro_use)]
 extern crate malloc_size_of;
-#[macro_use] extern crate malloc_size_of_derive;
-extern crate msg;
 extern crate net_traits;
 extern crate ordered_float;
 extern crate range;
 #[macro_use] extern crate serde;
 extern crate servo_arc;
-extern crate servo_geometry;
 extern crate servo_url;
 #[macro_use] extern crate servo_atoms;
 #[cfg(feature = "unstable")]
@@ -66,9 +63,6 @@ extern crate xi_unicode;
 #[cfg(target_os = "android")]
 extern crate xml5ever;
 
-#[deny(unsafe_code)]
-pub mod display_list;
-
 // Fonts
 #[macro_use] pub mod font;
 pub mod font_cache_thread;