Remove the need to destructure InlineFragments

We do this by moving InlineFragmentMap::fixup into InlineFragments

src/components/main/layout/construct.rs

@@ -307,23 +307,17 @@ impl<'a> FlowConstructor<'a> {
                                           whitespace_stripping: WhitespaceStrippingMode,
                                           node: &ThreadSafeLayoutNode) {
         let mut fragments = fragment_accumulator.finish();
-        if fragments.len() == 0 {
-            return
-        }
+        if fragments.is_empty() { return };
 
         match whitespace_stripping {
             NoWhitespaceStripping => {}
             StripWhitespaceFromStart => {
-                strip_ignorable_whitespace_from_start(&mut fragments);
-                if fragments.len() == 0 {
-                    return
-                }
+                fragments.strip_ignorable_whitespace_from_start();
+                if fragments.is_empty() { return };
             }
             StripWhitespaceFromEnd => {
-                strip_ignorable_whitespace_from_end(&mut fragments);
-                if fragments.len() == 0 {
-                    return
-                }
+                fragments.strip_ignorable_whitespace_from_end();
+                if fragments.is_empty() { return };
             }
         }
 
@@ -1084,58 +1078,3 @@ impl<'ln> ObjectElement for ThreadSafeLayoutNode<'ln> {
         }
     }
 }
-
-/// Strips ignorable whitespace from the start of a list of fragments.
-fn strip_ignorable_whitespace_from_start(fragments: &mut InlineFragments) {
-    if fragments.len() == 0 {
-        return
-    }
-
-    let InlineFragments {
-        fragments: old_fragments,
-        map: mut map
-    } = mem::replace(fragments, InlineFragments::new());
-
-    // FIXME(#2264, pcwalton): This is slow because vector shift is broken. :(
-    let mut found_nonwhitespace = false;
-    let mut new_fragments = Vec::new();
-    for fragment in old_fragments.iter() {
-        if !found_nonwhitespace && fragment.is_whitespace_only() {
-            debug!("stripping ignorable whitespace from start");
-            continue
-        }
-
-        found_nonwhitespace = true;
-        new_fragments.push(fragment.clone())
-    }
-
-    map.fixup(old_fragments.as_slice(), new_fragments.as_slice());
-    *fragments = InlineFragments {
-        fragments: new_fragments,
-        map: map,
-    }
-}
-
-/// Strips ignorable whitespace from the end of a list of fragments.
-fn strip_ignorable_whitespace_from_end(fragments: &mut InlineFragments) {
-    if fragments.len() == 0 {
-        return
-    }
-
-    let InlineFragments {
-        fragments: old_fragments,
-        map: mut map
-    } = mem::replace(fragments, InlineFragments::new());
-
-    let mut new_fragments = old_fragments.clone();
-    while new_fragments.len() > 0 && new_fragments.as_slice().last().get_ref().is_whitespace_only() {
-        debug!("stripping ignorable whitespace from end");
-        drop(new_fragments.pop());
-    }
-
-    map.fixup(old_fragments.as_slice(), new_fragments.as_slice());
-    *fragments = InlineFragments {
-        fragments: new_fragments,
-        map: map,
-    }
-}