diff --git a/components/layout/fragment.rs b/components/layout/fragment.rs
index db3a42a0669..ef7d3008e17 100644
--- a/components/layout/fragment.rs
+++ b/components/layout/fragment.rs
@@ -256,6 +256,8 @@ fn clamp_size(size: Au,
 pub enum GeneratedContentInfo {
     ListItem,
     ContentItem(ContentItem),
+    /// Placeholder for elements with generated content that did not generate any fragments.
+    Empty,
 }
 
 /// A hypothetical box (see CSS 2.1 § 10.3.7) for an absolutely-positioned block that was declared
@@ -1291,8 +1293,9 @@ impl Fragment {
     }
 
     /// Returns true if and only if this fragment is a generated content fragment.
-    pub fn is_generated_content(&self) -> bool {
+    pub fn is_unscanned_generated_content(&self) -> bool {
         match self.specific {
+            SpecificFragmentInfo::GeneratedContent(box GeneratedContentInfo::Empty) => false,
             SpecificFragmentInfo::GeneratedContent(..) => true,
             _ => false,
         }
diff --git a/components/layout/generated_content.rs b/components/layout/generated_content.rs
index d6a2149237c..b0284c62d7e 100644
--- a/components/layout/generated_content.rs
+++ b/components/layout/generated_content.rs
@@ -180,6 +180,7 @@ impl<'a,'b> ResolveGeneratedContentFragmentMutator<'a,'b> {
                                                                list_style_type,
                                                                RenderingMode::Suffix(".\u{00a0}"))
                 }
+                GeneratedContentInfo::Empty |
                 GeneratedContentInfo::ContentItem(ContentItem::String(_)) => {
                     // Nothing to do here.
                 }
@@ -242,9 +243,14 @@ impl<'a,'b> ResolveGeneratedContentFragmentMutator<'a,'b> {
             }
         };
 
-        if let Some(new_info) = new_info {
-            fragment.specific = new_info
-        }
+        fragment.specific = match new_info {
+            Some(new_info) => new_info,
+            // If the fragment did not generate any content, replace it with a no-op placeholder
+            // so that it isn't processed again on the next layout.  FIXME (mbrubeck): When
+            // processing an inline flow, this traversal should be allowed to insert or remove
+            // fragments.  Then we can just remove these fragments rather than adding placeholders.
+            None => SpecificFragmentInfo::GeneratedContent(box GeneratedContentInfo::Empty)
+        };
     }
 
     fn reset_and_increment_counters_as_necessary(&mut self, fragment: &mut Fragment) {
diff --git a/components/layout/inline.rs b/components/layout/inline.rs
index 1212f8a3cfc..1045613b934 100644
--- a/components/layout/inline.rs
+++ b/components/layout/inline.rs
@@ -846,10 +846,8 @@ impl InlineFlow {
             first_line_indentation: Au(0),
         };
 
-        for fragment in &flow.fragments.fragments {
-            if fragment.is_generated_content() {
-                flow.base.restyle_damage.insert(RESOLVE_GENERATED_CONTENT)
-            }
+        if flow.fragments.fragments.iter().any(Fragment::is_unscanned_generated_content) {
+            flow.base.restyle_damage.insert(RESOLVE_GENERATED_CONTENT);
         }
 
         flow
diff --git a/components/layout/lib.rs b/components/layout/lib.rs
index 174125c3fd9..fa8a2231265 100644
--- a/components/layout/lib.rs
+++ b/components/layout/lib.rs
@@ -3,6 +3,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #![feature(as_unsafe_cell)]
+#![feature(box_patterns)]
 #![feature(box_syntax)]
 #![feature(custom_derive)]
 #![feature(mpsc_select)]
diff --git a/tests/wpt/metadata-css/css21_dev/html4/quotes-036.htm.ini b/tests/wpt/metadata-css/css21_dev/html4/quotes-036.htm.ini
deleted file mode 100644
index f79479fde90..00000000000
--- a/tests/wpt/metadata-css/css21_dev/html4/quotes-036.htm.ini
+++ /dev/null
@@ -1,3 +0,0 @@
-[quotes-036.htm]
-  type: reftest
-  expected: FAIL