`compositing`: Combine `webrender_traits` and `compositing_traits` (#36372)

These two traits both exposed different parts of the compositing API,
but now that the compositor doesn't depend directly on `script` any
longer and the `script_traits` crate has been split into the
`constellation_traits` crate, this can be finally be cleaned up without
causing circular dependencies. In addition, some unit tests for the
`IOPCompositor`'s scroll node tree are also moved into
`compositing_traits` as well.

Testing: This just combines two crates, so no new tests are necessary.
Fixes: #35984.
Signed-off-by: Martin Robinson <mrobinson@igalia.com>

Signed-off-by: Martin Robinson <mrobinson@igalia.com>

3 files changed, 2 insertions, 190 deletions

diff --git a/components/shared/script/Cargo.toml b/components/shared/script/Cargo.toml
index 49efbadc165..0d3690188fe 100644
--- a/components/shared/script/Cargo.toml
+++ b/components/shared/script/Cargo.toml
@@ -20,6 +20,7 @@ background_hang_monitor_api = { workspace = true }
 base = { workspace = true }
 bluetooth_traits = { workspace = true, optional = true }
 canvas_traits = { workspace = true }
+compositing_traits = { workspace = true }
 constellation_traits = { workspace = true }
 crossbeam-channel = { workspace = true }
 devtools_traits = { workspace = true }
@@ -42,5 +43,4 @@ stylo_atoms = { workspace = true }
 stylo_traits = { workspace = true }
 webgpu_traits = { workspace = true, optional = true }
 webrender_api = { workspace = true }
-webrender_traits = { workspace = true }
 webxr-api = { workspace = true, features = ["ipc"] }
diff --git a/components/shared/script/lib.rs b/components/shared/script/lib.rs
index 1a35f4f7486..5ee143b3cdd 100644
--- a/components/shared/script/lib.rs
+++ b/components/shared/script/lib.rs
@@ -18,6 +18,7 @@ use base::id::{BrowsingContextId, HistoryStateId, PipelineId, PipelineNamespaceI
 #[cfg(feature = "bluetooth")]
 use bluetooth_traits::BluetoothRequest;
 use canvas_traits::webgl::WebGLPipeline;
+use compositing_traits::CrossProcessCompositorApi;
 use constellation_traits::{
     AnimationTickType, LoadData, NavigationHistoryBehavior, ScriptToConstellationChan, ScrollState,
     StructuredSerializedData, WindowSizeType,
@@ -48,7 +49,6 @@ use stylo_atoms::Atom;
 use webgpu_traits::WebGPUMsg;
 use webrender_api::units::DevicePixel;
 use webrender_api::{DocumentId, ImageKey};
-use webrender_traits::CrossProcessCompositorApi;
 
 /// The initial data required to create a new layout attached to an existing script thread.
 #[derive(Debug, Deserialize, Serialize)]
diff --git a/components/shared/script/tests/compositor.rs b/components/shared/script/tests/compositor.rs
deleted file mode 100644
index fb8410cb282..00000000000
--- a/components/shared/script/tests/compositor.rs
+++ /dev/null
@@ -1,188 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
-
-use base::id::ScrollTreeNodeId;
-use euclid::Size2D;
-use webrender_api::units::LayoutVector2D;
-use webrender_api::{ExternalScrollId, PipelineId, ScrollLocation, SpatialId};
-use webrender_traits::display_list::{
-    AxesScrollSensitivity, ScrollSensitivity, ScrollTree, ScrollableNodeInfo,
-};
-
-fn add_mock_scroll_node(tree: &mut ScrollTree) -> ScrollTreeNodeId {
-    let pipeline_id = PipelineId(0, 0);
-    let num_nodes = tree.nodes.len();
-    let parent = if num_nodes > 0 {
-        Some(ScrollTreeNodeId {
-            index: num_nodes - 1,
-            spatial_id: SpatialId::new(num_nodes - 1, pipeline_id),
-        })
-    } else {
-        None
-    };
-
-    tree.add_scroll_tree_node(
-        parent.as_ref(),
-        SpatialId::new(num_nodes, pipeline_id),
-        Some(ScrollableNodeInfo {
-            external_id: ExternalScrollId(num_nodes as u64, pipeline_id),
-            scrollable_size: Size2D::new(100.0, 100.0),
-            scroll_sensitivity: AxesScrollSensitivity {
-                x: ScrollSensitivity::ScriptAndInputEvents,
-                y: ScrollSensitivity::ScriptAndInputEvents,
-            },
-            offset: LayoutVector2D::zero(),
-        }),
-    )
-}
-
-#[test]
-fn test_scroll_tree_simple_scroll() {
-    let mut scroll_tree = ScrollTree::default();
-    let pipeline_id = PipelineId(0, 0);
-    let id = add_mock_scroll_node(&mut scroll_tree);
-
-    let (scrolled_id, offset) = scroll_tree
-        .scroll_node_or_ancestor(
-            &id,
-            ScrollLocation::Delta(LayoutVector2D::new(-20.0, -40.0)),
-        )
-        .unwrap();
-    let expected_offset = LayoutVector2D::new(-20.0, -40.0);
-    assert_eq!(scrolled_id, ExternalScrollId(0, pipeline_id));
-    assert_eq!(offset, expected_offset);
-    assert_eq!(scroll_tree.get_node(&id).offset(), Some(expected_offset));
-
-    let (scrolled_id, offset) = scroll_tree
-        .scroll_node_or_ancestor(&id, ScrollLocation::Delta(LayoutVector2D::new(20.0, 40.0)))
-        .unwrap();
-    let expected_offset = LayoutVector2D::new(0.0, 0.0);
-    assert_eq!(scrolled_id, ExternalScrollId(0, pipeline_id));
-    assert_eq!(offset, expected_offset);
-    assert_eq!(scroll_tree.get_node(&id).offset(), Some(expected_offset));
-
-    // Scroll offsets must be negative.
-    let result = scroll_tree
-        .scroll_node_or_ancestor(&id, ScrollLocation::Delta(LayoutVector2D::new(20.0, 40.0)));
-    assert!(result.is_none());
-    assert_eq!(
-        scroll_tree.get_node(&id).offset(),
-        Some(LayoutVector2D::new(0.0, 0.0))
-    );
-}
-
-#[test]
-fn test_scroll_tree_simple_scroll_chaining() {
-    let mut scroll_tree = ScrollTree::default();
-
-    let pipeline_id = PipelineId(0, 0);
-    let parent_id = add_mock_scroll_node(&mut scroll_tree);
-    let unscrollable_child_id =
-        scroll_tree.add_scroll_tree_node(Some(&parent_id), SpatialId::new(1, pipeline_id), None);
-
-    let (scrolled_id, offset) = scroll_tree
-        .scroll_node_or_ancestor(
-            &unscrollable_child_id,
-            ScrollLocation::Delta(LayoutVector2D::new(-20.0, -40.0)),
-        )
-        .unwrap();
-    let expected_offset = LayoutVector2D::new(-20.0, -40.0);
-    assert_eq!(scrolled_id, ExternalScrollId(0, pipeline_id));
-    assert_eq!(offset, expected_offset);
-    assert_eq!(
-        scroll_tree.get_node(&parent_id).offset(),
-        Some(expected_offset)
-    );
-
-    let (scrolled_id, offset) = scroll_tree
-        .scroll_node_or_ancestor(
-            &unscrollable_child_id,
-            ScrollLocation::Delta(LayoutVector2D::new(-10.0, -15.0)),
-        )
-        .unwrap();
-    let expected_offset = LayoutVector2D::new(-30.0, -55.0);
-    assert_eq!(scrolled_id, ExternalScrollId(0, pipeline_id));
-    assert_eq!(offset, expected_offset);
-    assert_eq!(
-        scroll_tree.get_node(&parent_id).offset(),
-        Some(expected_offset)
-    );
-    assert_eq!(scroll_tree.get_node(&unscrollable_child_id).offset(), None);
-}
-
-#[test]
-fn test_scroll_tree_chain_when_at_extent() {
-    let mut scroll_tree = ScrollTree::default();
-
-    let pipeline_id = PipelineId(0, 0);
-    let parent_id = add_mock_scroll_node(&mut scroll_tree);
-    let child_id = add_mock_scroll_node(&mut scroll_tree);
-
-    let (scrolled_id, offset) = scroll_tree
-        .scroll_node_or_ancestor(&child_id, ScrollLocation::End)
-        .unwrap();
-
-    let expected_offset = LayoutVector2D::new(0.0, -100.0);
-    assert_eq!(scrolled_id, ExternalScrollId(1, pipeline_id));
-    assert_eq!(offset, expected_offset);
-    assert_eq!(
-        scroll_tree.get_node(&child_id).offset(),
-        Some(expected_offset)
-    );
-
-    // The parent will have scrolled because the child is already at the extent
-    // of its scroll area in the y axis.
-    let (scrolled_id, offset) = scroll_tree
-        .scroll_node_or_ancestor(
-            &child_id,
-            ScrollLocation::Delta(LayoutVector2D::new(0.0, -10.0)),
-        )
-        .unwrap();
-    let expected_offset = LayoutVector2D::new(0.0, -10.0);
-    assert_eq!(scrolled_id, ExternalScrollId(0, pipeline_id));
-    assert_eq!(offset, expected_offset);
-    assert_eq!(
-        scroll_tree.get_node(&parent_id).offset(),
-        Some(expected_offset)
-    );
-}
-
-#[test]
-fn test_scroll_tree_chain_through_overflow_hidden() {
-    let mut scroll_tree = ScrollTree::default();
-
-    // Create a tree with a scrollable leaf, but make its `scroll_sensitivity`
-    // reflect `overflow: hidden` ie not responsive to non-script scroll events.
-    let pipeline_id = PipelineId(0, 0);
-    let parent_id = add_mock_scroll_node(&mut scroll_tree);
-    let overflow_hidden_id = add_mock_scroll_node(&mut scroll_tree);
-    scroll_tree
-        .get_node_mut(&overflow_hidden_id)
-        .scroll_info
-        .as_mut()
-        .map(|info| {
-            info.scroll_sensitivity = AxesScrollSensitivity {
-                x: ScrollSensitivity::Script,
-                y: ScrollSensitivity::Script,
-            };
-        });
-
-    let (scrolled_id, offset) = scroll_tree
-        .scroll_node_or_ancestor(
-            &overflow_hidden_id,
-            ScrollLocation::Delta(LayoutVector2D::new(-20.0, -40.0)),
-        )
-        .unwrap();
-    let expected_offset = LayoutVector2D::new(-20.0, -40.0);
-    assert_eq!(scrolled_id, ExternalScrollId(0, pipeline_id));
-    assert_eq!(offset, expected_offset);
-    assert_eq!(
-        scroll_tree.get_node(&parent_id).offset(),
-        Some(expected_offset)
-    );
-    assert_eq!(
-        scroll_tree.get_node(&overflow_hidden_id).offset(),
-        Some(LayoutVector2D::new(0.0, 0.0))
-    );
-}