--- a/layout/base/PresShell.cpp
+++ b/layout/base/PresShell.cpp
@@ -592,29 +592,16 @@ bool PresShell::sDisableNonTestMouseEven
 
 mozilla::LazyLogModule PresShell::gLog("PresShell");
 
 mozilla::TimeStamp PresShell::sLastInputCreated;
 mozilla::TimeStamp PresShell::sLastInputProcessed;
 
 bool PresShell::sProcessInteractable = false;
 
-#ifdef DEBUG
-static void
-VerifyStyleTree(nsPresContext* aPresContext, nsFrameManager* aFrameManager)
-{
-  if (nsFrame::GetVerifyStyleTreeEnable()) {
-    NS_ERROR("stylo: cannot verify style tree with a ServoRestyleManager");
-  }
-}
-#define VERIFY_STYLE_TREE ::VerifyStyleTree(mPresContext, mFrameConstructor)
-#else
-#define VERIFY_STYLE_TREE
-#endif
-
 static bool gVerifyReflowEnabled;
 
 bool
 nsIPresShell::GetVerifyReflowEnable()
 {
 #ifdef DEBUG
   static bool firstTime = true;
   if (firstTime) {
@@ -1813,17 +1800,16 @@ PresShell::Initialize()
 
   if (Element* root = mDocument->GetRootElement()) {
     {
       nsAutoCauseReflowNotifier reflowNotifier(this);
       // Have the style sheet processor construct frame for the root
       // content object down
       mFrameConstructor->ContentInserted(
           root, nullptr, nsCSSFrameConstructor::InsertionKind::Sync);
-      VERIFY_STYLE_TREE;
 
       // Something in mFrameConstructor->ContentInserted may have caused
       // Destroy() to get called, bug 337586.
       NS_ENSURE_STATE(!mHaveShutDown);
     }
 
     // nsAutoCauseReflowNotifier (which sets up a script blocker) going out of
     // scope may have killed us too
@@ -4405,31 +4391,29 @@ PresShell::CharacterDataChanged(nsIConte
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected CharacterDataChanged");
   NS_PRECONDITION(aContent->OwnerDoc() == mDocument, "Unexpected document");
 
   nsAutoCauseReflowNotifier crNotifier(this);
 
   mPresContext->RestyleManager()->CharacterDataChanged(aContent, aInfo);
   mFrameConstructor->CharacterDataChanged(aContent, aInfo);
-  VERIFY_STYLE_TREE;
 }
 
 void
 PresShell::ContentStateChanged(nsIDocument* aDocument,
                                nsIContent* aContent,
                                EventStates aStateMask)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected ContentStateChanged");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
 
   if (mDidInitialize) {
     nsAutoCauseReflowNotifier crNotifier(this);
     mPresContext->RestyleManager()->ContentStateChanged(aContent, aStateMask);
-    VERIFY_STYLE_TREE;
   }
 }
 
 void
 PresShell::DocumentStatesChanged(nsIDocument* aDocument, EventStates aStateMask)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected DocumentStatesChanged");
   NS_PRECONDITION(aDocument == mDocument, "Unexpected aDocument");
@@ -4459,17 +4443,16 @@ PresShell::AttributeWillChange(Element* 
   // XXXwaterson it might be more elegant to wait until after the
   // initial reflow to begin observing the document. That would
   // squelch any other inappropriate notifications as well.
   if (mDidInitialize) {
     nsAutoCauseReflowNotifier crNotifier(this);
     mPresContext->RestyleManager()->AttributeWillChange(aElement, aNameSpaceID,
                                                         aAttribute, aModType,
                                                         aNewValue);
-    VERIFY_STYLE_TREE;
   }
 }
 
 void
 PresShell::AttributeChanged(Element* aElement,
                             int32_t aNameSpaceID,
                             nsAtom* aAttribute,
                             int32_t aModType,
@@ -4481,17 +4464,16 @@ PresShell::AttributeChanged(Element* aEl
   // XXXwaterson it might be more elegant to wait until after the
   // initial reflow to begin observing the document. That would
   // squelch any other inappropriate notifications as well.
   if (mDidInitialize) {
     nsAutoCauseReflowNotifier crNotifier(this);
     mPresContext->RestyleManager()->AttributeChanged(aElement, aNameSpaceID,
                                                      aAttribute, aModType,
                                                      aOldValue);
-    VERIFY_STYLE_TREE;
   }
 }
 
 void
 PresShell::ContentAppended(nsIContent* aFirstNewContent)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected ContentAppended");
   NS_PRECONDITION(aFirstNewContent->OwnerDoc() == mDocument,
@@ -4511,18 +4493,16 @@ PresShell::ContentAppended(nsIContent* a
   // Call this here so it only happens for real content mutations and
   // not cases when the frame constructor calls its own methods to force
   // frame reconstruction.
   mPresContext->RestyleManager()->ContentAppended(aFirstNewContent);
 
   mFrameConstructor->ContentAppended(
       aFirstNewContent,
       nsCSSFrameConstructor::InsertionKind::Async);
-
-  VERIFY_STYLE_TREE;
 }
 
 void
 PresShell::ContentInserted(nsIContent* aChild)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected ContentInserted");
   NS_PRECONDITION(aChild->OwnerDoc() == mDocument, "Unexpected document");
 
@@ -4536,18 +4516,16 @@ PresShell::ContentInserted(nsIContent* a
   // not cases when the frame constructor calls its own methods to force
   // frame reconstruction.
   mPresContext->RestyleManager()->ContentInserted(aChild);
 
   mFrameConstructor->ContentInserted(
       aChild,
       nullptr,
       nsCSSFrameConstructor::InsertionKind::Async);
-
-  VERIFY_STYLE_TREE;
 }
 
 void
 PresShell::ContentRemoved(nsIContent* aChild, nsIContent* aPreviousSibling)
 {
   NS_PRECONDITION(!mIsDocumentGone, "Unexpected ContentRemoved");
   NS_PRECONDITION(aChild->OwnerDoc() == mDocument, "Unexpected document");
   nsINode* container = aChild->GetParentNode();
@@ -4583,19 +4561,16 @@ PresShell::ContentRemoved(nsIContent* aC
                                     oldNextSibling,
                                     nsCSSFrameConstructor::REMOVE_CONTENT);
 
   // NOTE(emilio): It's important that this goes after the frame constructor
   // stuff, otherwise the frame constructor can't see elements which are
   // display: contents / display: none, because we'd have cleared all the style
   // data from there.
   mPresContext->RestyleManager()->ContentRemoved(aChild, oldNextSibling);
-
-
-  VERIFY_STYLE_TREE;
 }
 
 void
 PresShell::NotifyCounterStylesAreDirty()
 {
   nsAutoCauseReflowNotifier reflowNotifier(this);
   mFrameConstructor->NotifyCounterStylesAreDirty();
 }
@@ -4620,17 +4595,16 @@ PresShell::ReconstructFrames()
   mDocument->FlushPendingNotifications(FlushType::Style);
 
   if (mIsDestroying) {
     return;
   }
 
   nsAutoCauseReflowNotifier crNotifier(this);
   mFrameConstructor->ReconstructDocElementHierarchy(nsCSSFrameConstructor::InsertionKind::Sync);
-  VERIFY_STYLE_TREE;
 }
 
 void
 nsIPresShell::RestyleForCSSRuleChanges()
 {
   if (mIsDestroying) {
     // We don't want to mess with restyles at this point
     return;
@@ -9772,22 +9746,16 @@ void
 PresShell::ListStyleSheets(FILE *out, int32_t aIndent)
 {
   int32_t sheetCount = mStyleSet->SheetCount(SheetType::Doc);
   for (int32_t i = 0; i < sheetCount; ++i) {
     mStyleSet->StyleSheetAt(SheetType::Doc, i)->List(out, aIndent);
     fputs("\n", out);
   }
 }
-
-void
-PresShell::VerifyStyleTree()
-{
-  VERIFY_STYLE_TREE;
-}
 #endif
 
 //=============================================================
 //=============================================================
 //-- Debug Reflow Counts
 //=============================================================
 //=============================================================
 #ifdef MOZ_REFLOW_PERF

--- a/layout/base/PresShell.h
+++ b/layout/base/PresShell.h
@@ -315,17 +315,16 @@ public:
   void SetPaintFrameCount(bool aOn) override;
   bool IsPaintingFrameCounts() override;
 #endif
 
 #ifdef DEBUG
   void ListComputedStyles(FILE *out, int32_t aIndent = 0) override;
 
   void ListStyleSheets(FILE *out, int32_t aIndent = 0) override;
-  void VerifyStyleTree() override;
 #endif
 
   static LazyLogModule gLog;
 
   void DisableNonTestMouseEvents(bool aDisable) override;
 
   void UpdateCanvasBackground() override;
 

--- a/layout/base/RestyleManager.cpp
+++ b/layout/base/RestyleManager.cpp
@@ -621,28 +621,16 @@ RestyleManager::ChangeHintToString(nsCha
 
 /**
  * Frame construction helpers follow.
  */
 #ifdef DEBUG
 static bool gInApplyRenderingChangeToTree = false;
 #endif
 
-#ifdef DEBUG
-
-void
-RestyleManager::DebugVerifyStyleTree(nsIFrame* aFrame)
-{
-  // XXXheycam For now, we know that we don't use the same inheritance
-  // hierarchy for certain cases, so just skip these assertions until
-  // we work out what we want to assert (bug 1322570).
-}
-
-#endif // DEBUG
-
 /**
  * Sync views on aFrame and all of aFrame's descendants (following placeholders),
  * if aChange has nsChangeHint_SyncFrameView.
  * Calls DoApplyRenderingChangeToTree on all aFrame's out-of-flow descendants
  * (following placeholders), if aChange has nsChangeHint_RepaintFrame.
  * aFrame should be some combination of nsChangeHint_SyncFrameView,
  * nsChangeHint_RepaintFrame, nsChangeHint_UpdateOpacityLayer and
  * nsChangeHint_SchedulePaint, nothing else.
@@ -1706,34 +1694,16 @@ RestyleManager::ProcessRestyledFrames(ns
         frameConstructor->UpdateTableCellSpans(content);
       }
       if (hint & nsChangeHint_VisibilityChange) {
         frame->UpdateVisibleDescendantsState();
       }
     }
   }
 
-#ifdef DEBUG
-  // Verify the style tree.  Note that this needs to happen once we've
-  // processed the whole list, since until then the tree is not in fact in a
-  // consistent state.
-  for (const nsStyleChangeData& data : aChangeList) {
-    // reget frame from content since it may have been regenerated...
-    if (data.mContent) {
-      nsIFrame* frame = data.mContent->GetPrimaryFrame();
-      if (frame) {
-        DebugVerifyStyleTree(frame);
-      }
-    } else if (!data.mFrame || !data.mFrame->IsViewportFrame()) {
-      NS_WARNING("Unable to test style tree integrity -- no content node "
-                 "(and not a viewport frame)");
-    }
-  }
-#endif
-
   aChangeList.Clear();
 }
 
 /* static */ uint64_t
 RestyleManager::GetAnimationGenerationForFrame(nsIFrame* aFrame)
 {
   EffectSet* effectSet = EffectSet::GetEffectSet(aFrame);
   return effectSet ? effectSet->GetAnimationGeneration() : 0;

--- a/layout/base/nsIPresShell.h
+++ b/layout/base/nsIPresShell.h
@@ -1064,17 +1064,16 @@ public:
   virtual bool IsPaintingFrameCounts() = 0;
 #endif
 
 #ifdef DEBUG
   // Debugging hooks
   virtual void ListComputedStyles(FILE *out, int32_t aIndent = 0) = 0;
 
   virtual void ListStyleSheets(FILE *out, int32_t aIndent = 0) = 0;
-  virtual void VerifyStyleTree() = 0;
 #endif
 
 #ifdef ACCESSIBILITY
   /**
    * Return true if accessibility is active.
    */
   static bool IsAccessibilityActive();
 

--- a/layout/generic/nsFrame.cpp
+++ b/layout/generic/nsFrame.cpp
@@ -305,35 +305,16 @@ bool nsFrame::GetShowEventTargetFrameBor
 }
 
 /**
  * Note: the log module is created during library initialization which
  * means that you cannot perform logging before then.
  */
 mozilla::LazyLogModule nsFrame::sFrameLogModule("frame");
 
-static mozilla::LazyLogModule sStyleVerifyTreeLogModuleInfo("styleverifytree");
-
-static uint32_t gStyleVerifyTreeEnable = 0x55;
-
-bool
-nsFrame::GetVerifyStyleTreeEnable()
-{
-  if (gStyleVerifyTreeEnable == 0x55) {
-      gStyleVerifyTreeEnable = 0 != (int)((mozilla::LogModule*)sStyleVerifyTreeLogModuleInfo)->Level();
-  }
-  return gStyleVerifyTreeEnable;
-}
-
-void
-nsFrame::SetVerifyStyleTreeEnable(bool aEnabled)
-{
-  gStyleVerifyTreeEnable = aEnabled;
-}
-
 #endif
 
 NS_DECLARE_FRAME_PROPERTY_DELETABLE(AbsoluteContainingBlockProperty,
                                     nsAbsoluteContainingBlock)
 
 bool
 nsIFrame::HasAbsolutelyPositionedChildren() const {
   return IsAbsoluteContainer() && GetAbsoluteContainingBlock()->HasAbsoluteFrames();

--- a/layout/generic/nsFrame.h
+++ b/layout/generic/nsFrame.h
@@ -701,58 +701,42 @@ private:
   NS_IMETHODIMP RefreshSizeCache(nsBoxLayoutState& aState);
 
   // Returns true if this frame has any kind of CSS animations.
   bool HasCSSAnimations();
 
   // Returns true if this frame has any kind of CSS transitions.
   bool HasCSSTransitions();
 
+public:
+
 #ifdef DEBUG_FRAME_DUMP
-public:
   /**
    * Get a printable from of the name of the frame type.
    * XXX This should be eliminated and we use GetType() instead...
    */
   nsresult GetFrameName(nsAString& aResult) const override;
   nsresult MakeFrameName(const nsAString& aKind, nsAString& aResult) const;
   // Helper function to return the index in parent of the frame's content
   // object. Returns -1 on error or if the frame doesn't have a content object
   static int32_t ContentIndexInContainer(const nsIFrame* aFrame);
 #endif
 
 #ifdef DEBUG
-public:
-  /**
-   * See if style tree verification is enabled. To enable style tree
-   * verification add "styleverifytree:1" to your MOZ_LOG
-   * environment variable (any non-zero debug level will work). Or,
-   * call SetVerifyStyleTreeEnable with true.
-   */
-  static bool GetVerifyStyleTreeEnable();
-
-  /**
-   * Set the verify-style-tree enable flag.
-   */
-  static void SetVerifyStyleTreeEnable(bool aEnabled);
-
   static mozilla::LazyLogModule sFrameLogModule;
 
   // Show frame borders when rendering
   static void ShowFrameBorders(bool aEnable);
   static bool GetShowFrameBorders();
 
   // Show frame border of event target
   static void ShowEventTargetFrameBorder(bool aEnable);
   static bool GetShowEventTargetFrameBorder();
-
 #endif
 
-public:
-
   static void PrintDisplayList(nsDisplayListBuilder* aBuilder,
                                const nsDisplayList& aList,
                                bool aDumpHtml = false)
   {
     std::stringstream ss;
     PrintDisplayList(aBuilder, aList, ss, aDumpHtml);
     fprintf_stderr(stderr, "%s", ss.str().c_str());
   }