--- a/layout/style/ServoBindings.cpp
+++ b/layout/style/ServoBindings.cpp
@@ -124,39 +124,16 @@ ThreadSafeGetDefaultFontHelper(const nsP
 
 void
 AssertIsMainThreadOrServoLangFontPrefsCacheLocked()
 {
   MOZ_ASSERT(NS_IsMainThread() || sServoFFILock->LockedForWritingByCurrentThread());
 }
 
 
-void
-Gecko_RecordTraversalStatistics(uint32_t total, uint32_t parallel,
-                                uint32_t total_t, uint32_t parallel_t,
-                                uint32_t total_s, uint32_t parallel_s)
-{
-
-#ifdef NIGHTLY_BUILD
-  // we ignore cases where a page just didn't restyle a lot
-  if (total > 30) {
-    uint32_t percent = parallel * 100 / total;
-    Telemetry::Accumulate(Telemetry::STYLO_PARALLEL_RESTYLE_FRACTION, percent);
-  }
-  if (total_t > 0) {
-    uint32_t percent = parallel_t * 100 / total_t;
-    Telemetry::Accumulate(Telemetry::STYLO_PARALLEL_RESTYLE_FRACTION_WEIGHTED_TRAVERSED, percent);
-  }
-  if (total_s > 0) {
-    uint32_t percent = parallel_s * 100 / total_s;
-    Telemetry::Accumulate(Telemetry::STYLO_PARALLEL_RESTYLE_FRACTION_WEIGHTED_STYLED, percent);
-  }
-#endif
-}
-
 /*
  * Does this child count as significant for selector matching?
  *
  * See nsStyleUtil::IsSignificantChild for details.
  */
 bool
 Gecko_IsSignificantChild(RawGeckoNodeBorrowed aNode, bool aTextIsSignificant,
                          bool aWhitespaceIsSignificant)

--- a/layout/style/ServoBindings.h
+++ b/layout/style/ServoBindings.h
@@ -147,20 +147,16 @@ struct FontSizePrefs
 };
 
 struct MediumFeaturesChangedResult {
   bool mAffectsDocumentRules;
   bool mAffectsNonDocumentRules;
   bool mUsesViewportUnits;
 };
 
-// DOM Traversal.
-void Gecko_RecordTraversalStatistics(uint32_t total, uint32_t parallel,
-                                     uint32_t total_t, uint32_t parallel_t,
-                                     uint32_t total_s, uint32_t parallel_s);
 bool Gecko_IsSignificantChild(RawGeckoNodeBorrowed node,
                               bool text_is_significant,
                               bool whitespace_is_significant);
 RawGeckoNodeBorrowedOrNull Gecko_GetLastChild(RawGeckoNodeBorrowed node);
 RawGeckoNodeBorrowedOrNull Gecko_GetFlattenedTreeParentNode(RawGeckoNodeBorrowed node);
 RawGeckoElementBorrowedOrNull Gecko_GetBeforeOrAfterPseudo(RawGeckoElementBorrowed element, bool is_before);
 nsTArray<nsIContent*>* Gecko_GetAnonymousContentForElement(RawGeckoElementBorrowed element);
 void Gecko_DestroyAnonymousContentList(nsTArray<nsIContent*>* anon_content);

--- a/toolkit/components/telemetry/Histograms.json
+++ b/toolkit/components/telemetry/Histograms.json
@@ -13919,46 +13919,16 @@
     "alert_emails": ["gfx-telemetry-alerts@mozilla.com","rhunt@mozilla.com"],
     "expires_in_version": "66",
     "kind": "exponential",
     "high": 200,
     "n_buckets": 50,
     "description": "Amount of time in milliseconds the main thread spends waiting for the paint thread to complete, if the time was greater than 200us.",
     "bug_numbers": [1386968]
   },
-  "STYLO_PARALLEL_RESTYLE_FRACTION": {
-    "record_in_processes": ["content"],
-    "alert_emails": ["manish@mozilla.com"],
-    "expires_in_version": "60",
-    "kind": "linear",
-    "high": 100,
-    "n_buckets": 50,
-    "description": "Percentage of restyles on a single page that were parallel",
-    "bug_numbers": [1421195]
-  },
-  "STYLO_PARALLEL_RESTYLE_FRACTION_WEIGHTED_TRAVERSED": {
-    "record_in_processes": ["content"],
-    "alert_emails": ["manish@mozilla.com"],
-    "expires_in_version": "60",
-    "kind": "linear",
-    "high": 100,
-    "n_buckets": 50,
-    "description": "Percentage of restyles on a single page that were parallel, weighted by elements traversed",
-    "bug_numbers": [1421195]
-  },
-  "STYLO_PARALLEL_RESTYLE_FRACTION_WEIGHTED_STYLED": {
-    "record_in_processes": ["content"],
-    "alert_emails": ["manish@mozilla.com"],
-    "expires_in_version": "60",
-    "kind": "linear",
-    "high": 100,
-    "n_buckets": 50,
-    "description": "Percentage of restyles on a single page that were parallel, weighted by elements styled",
-    "bug_numbers": [1421195]
-  },
   "PREFERENCES_FILE_LOAD_TIME_US": {
     "record_in_processes": ["main", "content"],
     "expires_in_version": "62",
     "kind": "exponential",
     "high": 1000000,
     "n_buckets": 20,
     "keyed": true,
     "description": "The time (in microseconds) to load, parse and process each prefs file, keyed by filename.",