style: Move invalidation::element::collector to invalidation::element::state_and_attributes.

Since it's what that file is about.

components/style/data.rs

@@ -246,8 +246,8 @@ impl ElementData {
             return InvalidationResult::empty();
         }
 
-        use invalidation::element::collector::StateAndAttrInvalidationProcessor;
         use invalidation::element::invalidator::TreeStyleInvalidator;
+        use invalidation::element::state_and_attributes::StateAndAttrInvalidationProcessor;
 
         debug!("invalidate_style_if_needed: {:?}, flags: {:?}, has_snapshot: {}, \
                 handled_snapshot: {}, pseudo: {:?}",

components/style/invalidation/element/mod.rs

@@ -4,8 +4,8 @@
 
 //! Invalidation of element styles due to attribute or style changes.
 
-pub mod collector;
 pub mod element_wrapper;
 pub mod invalidation_map;
 pub mod invalidator;
 pub mod restyle_hints;
+pub mod state_and_attributes;