Introduce a ClipRenderContext.

This groups together rendering-related arguments passed to the clip tree
update codepath.

webrender/src/clip_node.rs

@@ -4,9 +4,7 @@
 
 use api::DevicePixelScale;
 use clip::{ClipChain, ClipChainNode, ClipSourcesIndex, ClipStore, ClipWorkItem};
-use clip_scroll_tree::{ClipChainIndex};
-use gpu_cache::GpuCache;
-use resource_cache::ResourceCache;
+use clip_scroll_tree::{ClipChainIndex, ClipRenderContext};
 use spatial_node::SpatialNode;
 
 #[derive(Debug)]
@@ -32,13 +30,14 @@ impl ClipNode {
         &mut self,
         device_pixel_scale: DevicePixelScale,
         clip_store: &mut ClipStore,
-        resource_cache: &mut ResourceCache,
-        gpu_cache: &mut GpuCache,
+        render_context: &mut ClipRenderContext,
         clip_chains: &mut [ClipChain],
         spatial_nodes: &[SpatialNode],
     ) {
         let clip_sources = clip_store.get_mut(self.clip_sources_index);
-        clip_sources.update(gpu_cache, resource_cache, device_pixel_scale);
+        clip_sources.update(render_context.gpu_cache,
+                            render_context.resource_cache,
+                            device_pixel_scale);
         let spatial_node = &spatial_nodes[clip_sources.spatial_node_index.0];
 
         let (screen_inner_rect, screen_outer_rect) = clip_sources.get_screen_bounds(

webrender/src/clip_scroll_tree.rs

@@ -66,6 +66,11 @@ impl ClipChainIndex {
     pub const NO_CLIP: Self = ClipChainIndex(0);
 }
 
+pub struct ClipRenderContext<'a> {
+    pub resource_cache: &'a mut ResourceCache,
+    pub gpu_cache: &'a mut GpuCache,
+}
+
 pub struct ClipScrollTree {
     /// Nodes which determine the positions (offsets and transforms) for primitives
     /// and clips.
@@ -223,8 +228,7 @@ impl ClipScrollTree {
         screen_rect: &DeviceIntRect,
         device_pixel_scale: DevicePixelScale,
         clip_store: &mut ClipStore,
-        resource_cache: &mut ResourceCache,
-        gpu_cache: &mut GpuCache,
+        render_context: &mut ClipRenderContext,
         pan: WorldPoint,
         scene_properties: &SceneProperties,
     ) -> TransformPalette {
@@ -259,8 +263,7 @@ impl ClipScrollTree {
             clip_node.update(
                 device_pixel_scale,
                 clip_store,
-                resource_cache,
-                gpu_cache,
+                render_context,
                 &mut self.clip_chains,
                 &self.spatial_nodes,
             );

webrender/src/frame_builder.rs

@@ -6,7 +6,7 @@ use api::{BuiltDisplayList, ColorF, DeviceIntPoint, DeviceIntRect, DevicePixelSc
 use api::{DeviceUintPoint, DeviceUintRect, DeviceUintSize, DocumentLayer, FontRenderMode};
 use api::{LayoutPoint, LayoutRect, LayoutSize, PipelineId, WorldPoint};
 use clip::{ClipChain, ClipStore};
-use clip_scroll_tree::{ClipScrollTree, SpatialNodeIndex};
+use clip_scroll_tree::{ClipRenderContext, ClipScrollTree, SpatialNodeIndex};
 use display_list_flattener::{DisplayListFlattener};
 use gpu_cache::GpuCache;
 use gpu_types::{PrimitiveHeaders, TransformPalette, UvRectKind};
@@ -330,15 +330,20 @@ impl FrameBuilder {
         resource_cache.begin_frame(frame_id);
         gpu_cache.begin_frame();
 
-        let transform_palette = clip_scroll_tree.update_tree(
-            &self.screen_rect.to_i32(),
-            device_pixel_scale,
-            &mut self.clip_store,
-            resource_cache,
-            gpu_cache,
-            pan,
-            scene_properties,
-        );
+        let transform_palette = {
+            let mut clip_render_context = ClipRenderContext {
+                resource_cache,
+                gpu_cache,
+            };
+            clip_scroll_tree.update_tree(
+                &self.screen_rect.to_i32(),
+                device_pixel_scale,
+                &mut self.clip_store,
+                &mut clip_render_context,
+                pan,
+                scene_properties,
+            )
+        };
 
         self.update_scroll_bars(clip_scroll_tree, gpu_cache);