Bug 1298588 part 5. Store a ComputedValues on SharedStyleContext. r=bholley

components/layout_thread/lib.rs

@@ -118,6 +118,7 @@ use style::error_reporting::{ParseErrorReporter, StdoutErrorReporter};
 use style::logical_geometry::LogicalPoint;
 use style::media_queries::{Device, MediaType};
 use style::parser::ParserContextExtraData;
+use style::properties::ComputedValues;
 use style::servo::restyle_damage::{REFLOW, REFLOW_OUT_OF_FLOW, REPAINT, REPOSITION, STORE_OVERFLOW};
 use style::stylesheets::{Origin, Stylesheet, UserAgentStylesheets};
 use style::stylist::Stylist;
@@ -527,6 +528,11 @@ impl LayoutThread {
                 local_context_creation_data: Mutex::new(thread_local_style_context_creation_data),
                 timer: self.timer.clone(),
                 quirks_mode: self.quirks_mode.unwrap(),
+                // FIXME(bz): This isn't really right, but it's no more wrong
+                // than what we used to do.  See
+                // https://github.com/servo/servo/issues/14773 for fixing it
+                // properly.
+                default_computed_values: Arc::new(ComputedValues::initial_values().clone()),
             },
             image_cache_thread: Mutex::new(self.image_cache_thread.clone()),
             image_cache_sender: Mutex::new(self.image_cache_sender.clone()),

components/style/context.rs

@@ -13,6 +13,7 @@ use error_reporting::ParseErrorReporter;
 use euclid::Size2D;
 use matching::StyleSharingCandidateCache;
 use parking_lot::RwLock;
+use properties::ComputedValues;
 use std::collections::HashMap;
 use std::sync::{Arc, Mutex};
 use std::sync::mpsc::Sender;
@@ -82,6 +83,10 @@ pub struct SharedStyleContext {
 
     /// The QuirksMode state which the document needs to be rendered with
     pub quirks_mode: QuirksMode,
+
+    /// The default computed values to use for elements with no rules
+    /// applying to them.
+    pub default_computed_values: Arc<ComputedValues>,
 }
 
 /// A thread-local style context.

ports/geckolib/glue.rs

@@ -112,6 +112,7 @@ fn create_shared_context(per_doc_data: &PerDocumentStyleDataImpl) -> SharedStyle
         timer: Timer::new(),
         // FIXME Find the real QuirksMode information for this document
         quirks_mode: QuirksMode::NoQuirks,
+        default_computed_values: per_doc_data.default_computed_values.clone(),
     }
 }