style: Support full <image> syntax in list-style-image as per spec.

This allows supporting image-set(), etc, and simplifies the bullet frame
code significantly, too thanks to two changes:

  * Instead of manually managing the image request, use the CSS image
    loader, with the `REQUEST_REQUIRES_REFLOW` flag, to handle image
    loads correctly. This didn't exist when this code was initially
    implemented, but we can nicely use it now.

  * Instead of re-implementing another WebRender command-builder thing,
    we can just reuse the nsImageRenderer code.

Differential Revision: https://phabricator.services.mozilla.com/D100774

4 files changed, 7 insertions, 13 deletions

diff --git a/components/style/properties/longhands/list.mako.rs b/components/style/properties/longhands/list.mako.rs
index b50b961c735..82e226418cd 100644
--- a/components/style/properties/longhands/list.mako.rs
+++ b/components/style/properties/longhands/list.mako.rs
@@ -54,10 +54,10 @@ ${helpers.single_keyword(
 
 ${helpers.predefined_type(
     "list-style-image",
-    "url::ImageUrlOrNone",
+    "Image",
     engines="gecko servo-2013 servo-2020",
-    initial_value="computed::url::ImageUrlOrNone::none()",
-    initial_specified_value="specified::url::ImageUrlOrNone::none()",
+    initial_value="computed::Image::None",
+    initial_specified_value="specified::Image::None",
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-lists/#propdef-list-style-image",
     servo_restyle_damage="rebuild_and_reflow",
diff --git a/components/style/properties/shorthands/list.mako.rs b/components/style/properties/shorthands/list.mako.rs
index fd8cd8b1c23..f757c368cfa 100644
--- a/components/style/properties/shorthands/list.mako.rs
+++ b/components/style/properties/shorthands/list.mako.rs
@@ -10,7 +10,7 @@
                     derive_serialize="True"
                     spec="https://drafts.csswg.org/css-lists/#propdef-list-style">
     use crate::properties::longhands::{list_style_image, list_style_position, list_style_type};
-    use crate::values::specified::url::ImageUrlOrNone;
+    use crate::values::specified::Image;
 
     pub fn parse_value<'i, 't>(
         context: &ParserContext,
@@ -69,7 +69,7 @@
             (true, 2, None, None) => {
                 Ok(expanded! {
                     list_style_position: position,
-                    list_style_image: ImageUrlOrNone::none(),
+                    list_style_image: Image::None,
                     list_style_type: ListStyleType::None,
                 })
             }
@@ -83,14 +83,14 @@
             (true, 1, Some(list_style_type), None) => {
                 Ok(expanded! {
                     list_style_position: position,
-                    list_style_image: ImageUrlOrNone::none(),
+                    list_style_image: Image::None,
                     list_style_type: list_style_type,
                 })
             }
             (true, 1, None, None) => {
                 Ok(expanded! {
                     list_style_position: position,
-                    list_style_image: ImageUrlOrNone::none(),
+                    list_style_image: Image::None,
                     list_style_type: ListStyleType::None,
                 })
             }
diff --git a/components/style/values/computed/url.rs b/components/style/values/computed/url.rs
index 4815281a3bf..9f0d8f5bb3e 100644
--- a/components/style/values/computed/url.rs
+++ b/components/style/values/computed/url.rs
@@ -13,6 +13,3 @@ pub use crate::servo::url::{ComputedImageUrl, ComputedUrl};
 
 /// Computed <url> | <none>
 pub type UrlOrNone = GenericUrlOrNone<ComputedUrl>;
-
-/// Computed image <url> | <none>
-pub type ImageUrlOrNone = GenericUrlOrNone<ComputedImageUrl>;
diff --git a/components/style/values/specified/url.rs b/components/style/values/specified/url.rs
index b0a69b362d8..17ecbe0d5e8 100644
--- a/components/style/values/specified/url.rs
+++ b/components/style/values/specified/url.rs
@@ -13,6 +13,3 @@ pub use crate::servo::url::{SpecifiedImageUrl, SpecifiedUrl};
 
 /// Specified <url> | <none>
 pub type UrlOrNone = GenericUrlOrNone<SpecifiedUrl>;
-
-/// Specified image <url> | <none>
-pub type ImageUrlOrNone = GenericUrlOrNone<SpecifiedImageUrl>;