Bug 1781034 - Remove layout debugger's visual debugging. r=layout-reviewers,dshin

Differential Revision: https://phabricator.services.mozilla.com/D152628

layout/base/PresShell.h

@@ -1731,10 +1731,6 @@ class PresShell final : public nsStubDocumentObserver,
    */
   void NotifyDestroyingFrame(nsIFrame* aFrame);
 
-#ifdef DEBUG
-  nsIFrame* GetDrawEventTargetFrame() { return mDrawEventTargetFrame; }
-#endif
-
   bool GetZoomableByAPZ() const;
 
  private:
@@ -2833,14 +2829,11 @@ class PresShell final : public nsStubDocumentObserver,
   MOZ_CAN_RUN_SCRIPT_BOUNDARY bool VerifyIncrementalReflow();
   MOZ_CAN_RUN_SCRIPT_BOUNDARY void DoVerifyReflow();
   void VerifyHasDirtyRootAncestor(nsIFrame* aFrame);
-  void ShowEventTargetDebug();
 
   bool mInVerifyReflow = false;
   // The reflow root under which we're currently reflowing.  Null when
   // not in reflow.
   nsIFrame* mCurrentReflowRoot = nullptr;
-
-  nsIFrame* mDrawEventTargetFrame = nullptr;
 #endif  // #ifdef DEBUG
 
   // Send, and reset, the current per tick telemetry. This includes: