Make the DomTraversalContext own the SharedStyleContext and share it immutably across the traversal.

This allows us to get rid of a bunch of lifetimes and simplify a lot of code. It
also lets us get rid of that nasty lifetime transmute, which is awesome.

The situation with thread-local contexts is still suboptimal, but we fix that in
subsequent patches.

1 files changed, 7 insertions, 6 deletions

diff --git a/components/layout/sequential.rs b/components/layout/sequential.rs
index b4d31269629..e5f62fe1cea 100644
--- a/components/layout/sequential.rs
+++ b/components/layout/sequential.rs
@@ -5,7 +5,7 @@
 //! Implements sequential traversals over the DOM and flow trees.
 
 use app_units::Au;
-use context::{LayoutContext, SharedLayoutContext};
+use context::{LayoutContext, SharedLayoutContext, ThreadLocalLayoutContext};
 use display_list_builder::DisplayListBuildState;
 use euclid::point::Point2D;
 use floats::SpeculatedFloatPlacement;
@@ -16,13 +16,12 @@ use fragment::FragmentBorderBoxIterator;
 use generated_content::ResolveGeneratedContent;
 use gfx_traits::ScrollRootId;
 use servo_config::opts;
-use style::context::StyleContext;
 use style::servo::restyle_damage::{REFLOW, STORE_OVERFLOW};
 use traversal::{AssignBSizes, AssignISizes, BubbleISizes, BuildDisplayList};
 
 pub use style::sequential::traverse_dom;
 
-pub fn resolve_generated_content(root: &mut Flow, shared_layout_context: &SharedLayoutContext) {
+pub fn resolve_generated_content(root: &mut Flow, shared: &SharedLayoutContext) {
     fn doit(flow: &mut Flow, level: u32, traversal: &mut ResolveGeneratedContent) {
         if !traversal.should_process(flow) {
             return
@@ -35,13 +34,14 @@ pub fn resolve_generated_content(root: &mut Flow, shared_layout_context: &Shared
         }
     }
 
-    let layout_context = LayoutContext::new(shared_layout_context);
+    let tlc = ThreadLocalLayoutContext::new(shared);
+    let layout_context = LayoutContext::new(shared, &*tlc);
     let mut traversal = ResolveGeneratedContent::new(&layout_context);
     doit(root, 0, &mut traversal)
 }
 
 pub fn traverse_flow_tree_preorder(root: &mut Flow,
-                                   shared_layout_context: &SharedLayoutContext) {
+                                   shared: &SharedLayoutContext) {
     fn doit(flow: &mut Flow,
             assign_inline_sizes: AssignISizes,
             assign_block_sizes: AssignBSizes) {
@@ -58,7 +58,8 @@ pub fn traverse_flow_tree_preorder(root: &mut Flow,
         }
     }
 
-    let layout_context = LayoutContext::new(shared_layout_context);
+    let tlc = ThreadLocalLayoutContext::new(shared);
+    let layout_context = LayoutContext::new(shared, &*tlc);
 
     if opts::get().bubble_inline_sizes_separately {
         let bubble_inline_sizes = BubbleISizes { layout_context: &layout_context };